which type of extra achievement (other than academics) a fresher should have that make him different and better than other mba aspirants?

For a MBA aspirant to apply in a reputed college or top IIM you should have a good overall profile. Extracurricular activities wouldn't matter enough if you have a good score in your entrance test with required sectional cutoff and good academic record. It depend on you how you represent yourself to convert it.
In extracurricular activities there are like your participation in sports or any national level programme, got prizes or certificates, writting blogs etc.