Gst on works contract

Dear Members,

One of my client who is a works contractor doing contrac work in Tamilnadu Government Works from different departments namely, Highways, DRDA, PWD and Rural Works Departement. He signed various contracts (Works Contracts) before the implementation of GST i.e. before 01.07.2017. He got part payments on those works as per the existing Law (VAT) before implementation of GST. Presently he is drawing his part payments from the above mentioned departments. But now the Govt departments are not deducting VAT (5%) on those bills and nor they are paying GST Extra. My question is how can I show the receipts in GSTR3B and GSTR-1 returns ? Do I require to show it in my GST Returns ? Or I have to show it as Non-GST Outward Supply.

and Some Works all finished in VAT Period and received the Cheques on GST Period

How can I show the receipts in GSTR3B and GSTR-1 returns ? Do I require to show it in my GST Returns ? Or I have to show it as Non-GST Outward Supply

Show it as Non GST outward supply.
GST will not be payable on the supply after GST implementation where the consideration for the supply has been received before the appointed day AND the tax has already been paid under the earlier law.

It is immaterial whether the consideration for supply has been paid fully or partly.

For more clarification, Read below 3 case

Case 1

Mr. S supplies goods to Mr. B on a continuous basis. Mr. S. sent goods worth Rs. 1,00,000 on 15th July for which Mr. B made an advance payment on 27th June. Will GST apply?

GST will not apply to these goods as payment has already been received before GST implementation and tax was applied according to the earlier law.

Case 2

Based on above scenario, Mr. B had paid only Rs. 50,000 as an advance in June.

GST will still not apply as the tax was applied on basis of earlier law. It does not matter if the consideration was partly paid.

Case 3
Mr. B makes entire payment of 1,00,000 on 17th July.

GST will be applicable as consideration is received after GST implementation. However, if the tax had been paid under earlier law, then GST will not be applicable.