Hi Rhythm,

The JEE-Mains Examination is conducted for admissions to many Engineering colleges in India. It can only be used for admissions in institutes that accept JEE-Mains scores. The top institutes that take admissions on the basis of Mains are probably the NITs, IIITs and the GFITs. 90 percentile seems like a good enough score to get into these institutes. However, if you want to join IIT, you need to clear Mains and then obtain a high score in JEE-Advanced. It is recommended you check the entrance test accepted by the institute you are aiming for and then answer that test.