I want to make login and register from more one table

Please don't do this. You will regret it later.

Users are users. Their role might be different, and you can decide what they can do with authorisation once you have authenticated them.

If you can, authenticate all users using the same method.

Why not use roles for each? Have a role for each: doctor, student, and admin. Use the users table to provide login details and the other tables as their profile.

You can link the profile tables by adding user_id to them and adding the relationship to the models. You can use a package like spatie/laravel-permissions to manage the roles and permissions:

https://spatie.be/docs/laravel-permission/v5/introduction