Hii aspirant

Aggregate marks means the grand total marks obtained by the candidate, taken together for all the subjects, whether compulsory or optional.

Now for example if some exam eligiblity have 50% aggregate marks in PCB/PCM, so here you must get 150/300 by adding all three subject marks. Like if you get 70 in phy,55 in chem and 60 in math your aggregate marks is 185/300 and aggregate percentage is almost 62%

So you can calculate your aggregate marks in following manner.

Hope this information helps you

All the best