I would like to know whether the clutch cable is covered under warranty. If it is then what's the time period and under how much kilometres the bike should be?

Well, every manufacturing defect in the bike and its parts would be covered under the standard warranty. However, we would suggest you to refer the owners manual for complete details for a specific part or you may exchange your words with the authorised service centre for the same. You may check out nearest authorised service centre details.