Dear Rakesh,
For Leave Carry forward, you need to check existing system, if you had written PCR (PT60) then you don't need to anything, if you don't have pcr then you need to find out remaining balance & then upload the same in it2013 for that particular Quota type for transfer & it0416 (not mandatory depends of validity of leave) for deduction.
How you will generate leave & what is validity period of your leaves.