Hello!

It is not necessary to do MCA after completion of BCA, you can also do MS .

M.S. degree is a good option for students who want to go for further higher studies or for those who are about commiting to Ph.D.

MCA is good option for those who want to start their career in System Engineer, Database Administrator, System analyst, Software Consultant, Test Engineer, designer , Mobile application developer, computer network architect ,IT manager, Information Security Officer, Security Architect, Security Director, Network Security Engineer

Both the courses are good just choose acoording to your preference.

Thank you!

Hope it helps!