Reduction in set off under rule 53(2)(a) of mvat rules

Hello,

I have an query regarding reduction in set off under Rule 53(2)(a) i.e. Sale of Tax Exempted goods(SCH A) manufactured by assessee. Is this reduction is also applicable on CST sales of Tax Free goods?

My another query is related to Revision of return.If we have not made reduction in set-off in earlier return, then instead of revising return can we make adjustment of the same under subsequent return i.e in Form 231 in point no. 9 (e)??