whether question of caste comes under civil law

Deepak, are you referring to Section 9 of the CPC?

yes sir , i m in doubt there it is said matter relating to caste doesn't come under civil suit then under which category it falls

As far as the question of caste is concerned, it is the members of the caste alone that can determined whethera person belongs to a particular caste or not, and not by the court. If the members of a particular commuity  decide it that should be final.