its can be various number of problems...
Are you sure that your amp, subs are working?

Are you using the factory HU or aftermarket HU? If you are using the factory HU which has no RCA output, so you used a RCA adapter, make sure that you connect that RCA adapter up properly...

"the RCA has two pair one is for input n tha other is for output because i think that it is tha RCA jacks"

I assume you're using 1 pair of RCA (which had 2 heads at each end) if this 1000w kenwood is a mono...

The problem could be from you wiring the RCA the wrong way....check the RCA connection from the HU to the amp....check for the reverse of the RCA...which if it happen...then it doesn't produce sound
check here read more about it.... www.bcae1.com

and your post doesn't list not enough info. for other to predict the problem...