Generating simple and complex passwords

I prefer

import tkinter as tk

and I can see that tk.Button, tk.INSERT, tk.FALSE are not my local variables/classes.

You can use string.ascii_lowercase instead of letters list, and string.ascii_uppercase instead of capital.

You don't have to convert string.ascii_lowercase and string.ascii_uppercase into list.

https://docs.python.org/3/library/string.html

password1 and password2 are local variables so you can use one name password in both functions.

for loop put in two lines - to make it more readable.

for child in frame.winfo_children():
    child.grid_configure(padx=5, pady=10)

In comments you can put one space after # - to make it more readable. You can put one space after every , .

You can use "" directly with join

"".join(password1)

You don't need ()

around text_frame in

tk.Text((text_frame), ...

# OK
tk.Text(text_frame, ...

around capitol in

choice((capital))

# OK
choice(capital)

around letters in

choice((letters))

# OK
choice(letters)

You can add empty lines in functions to separate some part of functions

In complex_password you can randint(1, 2) instead randint(1, 4) because it gives the same probability - 50% for letter and 50% for number.

In complex_password you can use for loop instead while and don't need variable count.

In complex_password you don't need if count == 12 because this part can be outside while/for loop.

You can organize code this way

import tkinter as tk
from tkinter import ttk
import random
import string

# === constants === (UPPER_CASE names)

    # empty

# === classes === (CamelCase names)

    # empty

# === functions === (lower_case names)

def complex_password(): #complex password function
    password = []

    password.append(random.choice(capital))

    for __ in range(12):
        roll = random.randint(1, 2)

        if roll == 1:
            password.append(random.choice(letters))
        else:
            number = random.randint(0, 9)
            number = str(number)
            password.append(number)

    password = "".join(password)

    text.insert(tk.INSERT, password)
    text.insert(tk.INSERT, "\n")

def simple_password(): #simple password function
    password = []

    password.append(random.choice(words))
    password.append(random.choice(words))

    number = random.randint(1, 99)
    password.append(str(number))

    password = "".join(password)

    text.insert(tk.INSERT, password)
    text.insert(tk.INSERT, "\n")

def clear_text(): #clear txt box function
    text.delete(1.0, tk.END)

# === main ===

# --- some variables ---

words = [
    'Dog', 'Cat', 'Mouse', 'Fire', 'Ice', 'Basket', 'Tree', 'Tiger',
     'Lion', 'Flash','Super', 'Light', 'Zoom','Speed', 'Pants', 'Shirt',
     'Hat', 'Suit', 'Berry', 'Yogurt', 'Epic', 'Keyboard', 'Toe', 'Car',
     'Truck', 'Bike', 'Motor', 'Hammer', 'Pizza', 'Heart', 'Arm','Joint',
     'Saw', 'New', 'Carrots', 'Baby', 'Kiss', 'Backspace',  'Enter', 'Alt',
     'Print', "Down", 'Up', 'Question', 'Rain', 'Forest','Red', 'Orange',
     'Yellow', 'Green', 'Blue', 'Purple', 'Brown', 'Black', 'Indigo', 'Grey',
     'Shadow', 'Eye', 'Brick', 'Twig', 'Gangster', 'Thug', 'Chains', 'Gold',
     'Silver', 'Bronze', 'Platinum', 'Titanium', 'Exploding', 'Ladybug', 'Grass',
     'Monkey', 'Rhino', 'Comma', 'Hair', 'Shark', 'Fish'
]

letters = string.ascii_lowercase
capital = string.ascii_uppercase

# --- init ---

main = tk.Tk()

main.title("Password Gen")
main.resizable(width=tk.FALSE, height=tk.FALSE)
main.geometry("238x230")

# --- objects ---

frame = ttk.Frame(main)
button_frame = ttk.Frame(frame)
text_frame = ttk.Frame(frame)
text = tk.Text(text_frame, borderwidth=10, height=8, width=20, relief="sunken")

# buttons
simple = ttk.Button(button_frame, text="Simple", command=simple_password)
complex = ttk.Button(button_frame, text="Complex", command=complex_password)
clear = ttk.Button(button_frame, text="Clear", command=clear_text)

# buttons grids
simple.grid(column=2, row=1)
complex.grid(column=1, row=1)
clear.grid(column=3, row=1)
text.grid()

# frame grids
frame.grid(column=1, row=2)
text_frame.grid(column=1, row=2)
button_frame.grid(column=1, row=1)

# misc settings
for child in frame.winfo_children():
    child.grid_configure(padx=5, pady=10)

# --- start the engine ---

main.mainloop()

Your code is quite confusing in some places. complex_password for example. Usually a function will return a value or run some process that modifies another value (eg a file on your computer or a class's attributes). It's unusual to see something like inserting the password result into a global object. It would be much nicer to return password2 and then call text.insert in the same place you call complex_password.

password = complex_password
text.insert(INSERT, password2)
text.insert(INSERT, "\n")

In your function you have a password2 but no password. If you were worried about duplicate names clashing then you needn't, password will just be a local value inside this function. It wont affect or be affected by other password values.

Instead of using a while loop with count, just use for _ in range(12):. That will loop twelve times with no need for a counter. Also x = "" is unnecessary, just call "".join.

This is how I'd rewrite the function:

def complex_password():

    password = [random.choice(capital)]
    for _ in range(12):
        roll = random.randint(1,2)
        if roll == 1:
            password.append(random.choice(letters))
        else:
            password.append(str(random.randint(0,9)))
    return ''.join(password)