Work Contract (if site situated in other state)

My client is a work contractor, which is registered & having TIN No. in Uttar Pradesh. He got a contract from a company, which is also registered under UPVAT Act having TIN Number & registered office at Lucknow. But site of this contract situated at other State i.e. Uttrakhand. 1- is this contract is valid for VAT purpose, because contractee comapny is not registered in Uttrakhand? 2- What will be the procedure of VAT calculation & billing? Plz suggest me, its urgent.