Hello,

Admission into different higher degree has different eligibility criteria.

1. for course like BSc, BBA, BCom:- whole 12th percentage is taken into consideration
2. for BA:- best 4 combination along with language paper in which candidate has otpted for admission like hindi, english is considered as one of the 4 best score
3. for engineering, medical:- PCM and PCB score/percentage is taken into consideration. maths and biology is compulsory subject for the respective streams. here 3 compulsory subject is considered.
4. for other streams, PC(M/B )  or PCMB score is taken into consideration.

in some college/university, they also keep requirements like good score in english or it must be a compulsory/mandatory subject.

so in 12th, 6 subjects are there basically, it may differ from different board but minimum 6 subject is there. if you choose for BSc, BCom, BBA for different streams, all the 6 subject aggregate / percentage is considered.

Hope it helps!