Here are some of the policies that you can set:

You can set a minimum length of the password, or you can ask the users to add at least one number or special characters in it.

You can assign requirements of particular character types, including uppercase letters, lowercase letters, numbers, and non-alphanumeric characters.

You can enforce automatic password expiration, prevent reuse of old passwords, and request for a password reset upon their next AWS sign in.

You can have the AWS users contact an account administrator when the user has allowed the password to expire.

https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_passwords_account-policy.html