Dear aspirant,

Both the papers are seperate those appearing for all 4 subjects( all 3 papers) can give then one after the other or when ever they are scheduled. I myself have appeared for maths physic&chem and bio paper in the same day with intervals of 30 mins between each paper of 100 marks.

see physics and chem are in one paper and you will be alloted one hour for that

then 30 mins break

followed by either maths of 1 hour

and then bio of 1 hour