ANkit,
You didn't mentioned where are you checking your forecast in SNP planning book or RRP3? If in SNP planning book, check the buckets for this planning book and compare the same with DP planning book.
I hope when you are doing a total in DP & SNP you are just considering future buckets but not past (considering from when you have released).
Also check whether it is getting consumed because of sales orders?
And share screen shots if not resolved.
Regards
Rahul