Currently estimated positions of Barak batteries and S-400 squadrons.
View attachment 42690
13 MRSAM batteries (80 km) and 3 S-400 squadrons (325 km).
There are a few more holes that need to be plugged, like Bikaner and Sirsa along Pakistan, they sit within the gap between Punjab and Rajasthan. Maybe it will be done soon.
18 batteries will plug most holes. Then we will need another 12-14 batteries, which will be covered by Akash NG; Ujjain, Agra, Halwara, Ambala, Hasimara, Chabua, Bhopal etc. But it could go beyond that due to the IAF's planned expansion.
As for the S-400, you will notice there are 5 circles rather than 6. It's possible one of the two sites, either Jodhpur or Punjab, have 4 batteries instead of 2. Or we just don't know the location of the 6th one. Bareilly and Gwalior may get S-400. And maybe Awantipore in Kashmir and the last one in Assam or Gorakhpur. 9 sites, 20 batteries.