Hello Meeradevi Loganathan,
Try check your steps in your setup application: App security → Acess role → module roles and entity acess, you need check if all its connect correct for specific role
If u have any doubt can check in “Become a Rapid Developer” (rapid level course) the module 9, they explains in detail the security acess for login it’s very good i think there u can resove your problem!!
NOTE: I’m not a expert yet, but can try to help you, hope this help!! :)
This might depend on the entity which is on the page you are trying to access. Please check your access rules on this entity.