Gst on mnrega

Please elaborate the query ? In case it falls under Work contact then yes.

I think No.

Services of Labour is Exempted from GST vide Mege Exemption Notification No. 12/2017 - Central Tax ( Rate ), dated 28.06.2017.

It will depend upon the case. In some cases contracts are made in such a way to cheat poor labourers. They do not even understand it because of high illiteracy among them. As also suggested by Nivesh Sir, it will be applicable in case it falls under Work Contract.
So I would ask you to provide some more information...

Govt department offered work order and supply order to a registered contractor under mnrega scheme. work done and supply made. confusion is that amount received in favour of work , is amount attract gst or not?

It's GST is applicable on MGNREGS materials components

There is no specific exemption. If work is of pure service in relation to the works entrusted to panchayat and/or Municipality mentioned in appropriate schedule or if the material involved is less than 25% of the total contract value, then exempted. 

If the work qualifies as works contract, then taxable as usual rate.