Where to live, prefer to rent rather than buy, would prefer a small house with privacy and small acerage around it. What are the NFA laws like?

NFA laws are pretty friendly; SBRs by state-law definition, qualify as handguns so you must have a CCW/LTCH to carry a SBR around. IIRC, if you're AD or reserves and you're being stationed there but maintaining permanent residence elsewhere your home-state CCW is recognized by IN, otherwise you'll have to get an IN LTCH (residents must have IN LTCH).

The rural homes surrounded by acreage might be all that is left for rentals; most people don't seem to want to rent "out in the country" but with the housing market really strong it seems it's becoming hard to find rentals. Many rural rentals around me that have sat vacant for a few years are all of the sudden becoming occupied (likely because the tenants couldn't find anything closer to town). I don't know the specifics of the Atterbury area though.

Rental prices tend to be artificially high in the area due to a large local employer. Your best bet would be to try and rent on the west side or northwest side of Atterbury.

I’m pcsing there in January and was wondering what town to live in around there and where I can go shooting at

Franklin or Trafalgar. Atterbury has a range.

Live North of Columbus / Bartholomew Co and Brown Co due to people being very proud of their property and charge accordingly.

Atterbury Range uses fixed distance firing lines, but has a nice facility.  Other clubs and ranges in the area have options to shoot a variable distances for handgun and long gun.

Area is ripe for civilian training opportunities.