Residuary powers with Parliament :
Article 248 of Constitution of India makes it clear that Parliament has exclusive powers to make any law in respect of any matter not enumerated in the Concurrent List or State List. These include the power of making any law imposing a tax not mentioned in Concurrent List or State List. This is also stated in entry 97 of List I of Seventh Schedule.
Thus, all residual powers are with Parliament i.e. Union Government.