GST reg Required for exempt sale?

If you are dealing exclusively in exempt goods you need not to take regsitration in GST.

But as you are registered under vat , you will be compulsorily migrated to GST and get provisional GSTIN.

You need to apply for cancelation of your provisional GSTIN.

Section 24 :

Notwithstanding anything contained in sub-section (1) of section 22, the following

categories of persons shall be required to be registered under this Act,––

(i) persons making any inter-State taxable supply;

If you are dealining exclusively in exempt goods/service no need to register.