hello, Rahul Rawani 

you can calculate your percentage easily by following the given steps.

step1: first you have to divide your marks by the total of 360 marks if suppose you got 345 then you should divide 345 by 360 (345/360).

step2: if you you want to calculate for the 100% then you have to multiply the step 1 with 100 ie. 345/360*100.

for example :

345/360= 0.958333

then multiply with 100 ie.

345/360*100

=0.95833*100

=95.833%

I hope you get a clearity about this issue.

All the best for your future.

thank you.