Hope you are doing good. Let me tell you about your chart (with the assumption that the time provided by you is exact).
Your are a gemini ascendant with natal moon in Virgo in the nakshatra of Chitra/Chitta
*Jupiter is favorably positioned for education in your birth chart: Natally it is placed in third house of secondary education and hence your secondary and higher secondary education must have been good and also it aspects higher education.
*During Jan 2009 to Jan 2010 when it was transiting Aquaris, you must have given your IIT entrance. Transiting 9th house it must have helped you reach IIT. Had you given your entrance during 2008 it must have not helped you clear your competitive exam and might have delayed you by a year of preparation.
Regarding other planets, you have venus and sun debilitated in Virgo and Libra respectively. (but this is not relevant to the question you asked)
You are currently running in to Rahu dasha and Moon bhukthi and also has Sade-Sati (7.5 years of Lord Shani's test) till the end of 2014. Even if you try hard you may not succeed before late 2015 during when your Jupiter Dasha would start and Sade Sati would end in parallel. When you give your exam when Jupiter is transiting in Leo, you would succeed. But remember the day you give your exam, Jupiter should be transiting Leo (going by the current trend, Jupiter moves to the next sign closely late May/early June in 2015 - If your exam is in early May, chances are less ~50%). In that 50% case, praying and performing pooja to Lord Dhakshinamurthy (Lord Shiva in the form Guru) can help you succeed in your preliminary exam as he is the Diety of Jupiter. You can also wear Rudraksha bead related to Jupiter (but other conditions apply).