I am right now in nirma university pursuing mechanical engineering but I want to do mba ahead so which university should I join?
You need to work hard for different MBA exams like CAT, XAT, CMAT etc. As these exams are also very competitive exams so you need to aim for a very high percentile in order to get a call from any top b-school for 2nd round of interview and WSAT. After this round only the final merit list is made on your overall performance and profile. Through which students are called for admission.
So currently your target should be to start preparing from basics for these MBA exams.
All the best for your preparations!!