The eligibility criteria for M.Des degree vary from university to university.

You should have a Bachelor's degree in Design or Architecture.

You must have  not scored  less than 50 % marks in aggregate in graduation.

You need to take Common Entrance Examination for Design (CEED) with percentile equal to or more than 75.

There is no age limit for CEED Exam.

Entrance test is followed by a process of personal interview.

I hope my answer helps. All the very best for your future endeavors!