Are only CET scores considered for issuing a rank or will the rank be issued on the basis of an aggregate of 12th/PUC and KCET scores? Also, will there be any consideration of marks for CBSE board if a rank is issued as an aggregate?

Usually both 2nd pu pcm marks and cet marks are considered for kcet ranking .But,this year ,as the 2nd pu exam was cancelled ,only cet marks were considered for declaring ranks
If the total marks were same then first preference was given to maths cet marks next physics and then chemistry
If students got same marks in every subject then preference was given to age difference .Elder one was given first preference