help required :(

i am in great confusion my profile is 10th -86% 12th -72.8% B.E. aggregate is 62% also am campus placed in IBM (network support job , 24x7 :/) ultimately i want to prep fr CAT and other entrances , but i am confused as i am too late dis year and i…

i am in great confusion my profile is 10th -86% 12th -72.8% B.E. aggregate is 62% also am campus placed in IBM (network support job , 24x7 :/) ultimately i want to prep fr CAT and other entrances , but i am confused as i am too late dis year and i wont be able to get top college, what should i do? Reject IBM offer and start preparing for CAT 2014 and other exams ? or join the company and leave after 6 months ie JAN(as there is no bond) and den strt prep for CAT 2014 , is 8-10 months enuf to prep thoroughly for CAT and other entrances ? i want to get top 20 colleges only, thats my target , please help thank you 😃