works contract under GST

Arjun Tripathi (168 Points)

20 September 2017  
I am govt contractor.I have taken contract of sanitation arrangements. In this contract i have purchased all things from gst non registered person.
If tender amount is 6 lacs but have quoted 1% below as 5.94 lacs as per 12% gst my tax liability will be 72000 i have purchased from gst non registered person I have followed RCM and Will pay 60000 rs gst and 12000 remaining as 72000- 60000=12000
1)Above calculation is correct?
2)Can I avail avail ITC on RCM and this type of govt contract?
3) 12%GST will be on 6lacs or below quoted amount which is 5.94 lacs?