12th percentage will not be considered there, only the score of JEE they will ask for. To get an idea about admission in the same, you can go through below points -
i) No separate merit list will be prepared. The provisional seat allotment will be based solely on the
All India Rank (AIR) of the candidate in the JEE (Main) 2017 examination as given by CBSE.
ii) For B. E. / B. Tech. programmes, All India Rank in Paper-1 of JEE (Main) 2017 will be considered.
iii) For B. Arch. at IGDTUW, All India Rank in Paper-2 of JEE (Main) 2017 will be considered.
iv) Other than above merit rank, provisional seat allotment will be done by considering all the details provided by the candidate in his/her ONLINE application like category, region, minimum qualification eligibility criterion, Choices filled etc.

Hope this helps!!!

Good Luck!!!