Gst rates on milling charges of government paddy

Hi Experts,

I want to ask two questions

1. what will be the GST rates on milling charges of Govt. Paddy as i heard any service related with state or centre govt will be exempted from GST but not sure.

2. If milling charges attracts 18% of GST then a rice miller can claim full input tax credits on all produts he purchased like machinery etc without reversal u/s 42 and 43