1.Why police has send information on ordinary paper i.e. there was no stamp or any thing ,just half page of regular notebook is used for that.
If you suspect some foul play in it, you may engage an advocate to confirm the real situation and fact of the case.
2.Is anticipatory bail is applicable in Uttar Pradesh.
I dont think there is a provision in UP for anticipatory bail.
3.What is procedure of anticipatory bail or Interim Bail.
Consult a local advocate
4.Can we do any counter FIR against the person and if possible where to do in same police station in Mau or in our police station at Varanasi.
What is your allegation or complaint for counter FIR?
5.What is average cost required in such case for Interim Bail in UP.
Depends on the advocate you may engage.
6.In the last enquiry, police has not given any copy of FIR, They denied to give. We have been told that the case is in Investigation.
You can ask your advocate to get a copy.