Hi Ajini,

You can first search the security groups in the Python code and then you can add users to it with a write operation. For example:

your_group = self.env.ref('your_module.skill_creator')
# Your filter criteria here: ​
users = self.env['res.users'].search([('name', '=', 'SomeCondition')])
for user in users:
    your_group.write({

        'users': [(4, user.id)]

    })  

Alternatively you can also remove a user from a group like this:

for user in users:
    your_group.write({
        'users': [(3, user.id)]
    })  

And finally to check if a user belongs to a group:

for user in users:
    if user.has_group('your_module.skill_creator'):
        # Your custom logic here - this user is within the group!

    if not user.has_group('your_module.skill_creator'):

        # Your custom logic here - this user is NOT within the group! 

Regards,

Yenthe