Stock in medical shop

Dear Experts.,

A medical shop running more than 10 years. But, No registered under State VAT Act.

Now, He/She get registration under State VAT Act on 30 th May 2017. He get Provisional ID & Password from GST.

My Question is.,

He have more stock on or before registration under VAT act. (Purchases after Registration Rs. 250,000 + Tax & Purchases Before Registration Rs. 750,000 + Tax).

Then, How to Treat above Stock & Input Tax  on GST...

Please reply....