Is we have to give 2 exams of Nmms to qualify

Yes, to qualify for the NMMS (National Means–cum–Merit Scholarship) exam, you must appear for two tests:

1. MAT (Mental Ability Test)

2. SAT (Scholastic Aptitude Test)

You need to pass both sections with the minimum qualifying marks (usually 40% for General and 32% for SC/ST).
Final selection is based on your combined score in MAT and SAT.

Hope you understand.