I have just bought a building at 10mm scale from Total Battles Miniatures (half-timbered cottage) Its beautiful model put it takes all of a hex (footprint is 80mm)
When I want to show a village, should I use 6mm buildings so units can occupy the hex? Also how many troops ie stands can occupy a town hex I cannot find anything in the rules that tells me about defending a town hex.
I initially also used 10mm scale buildings for games, but soon switched to 6mm. They look fine on the table, and, as you say, they allow more stands to be placed in the hex.
As for numbers of stands in a town hex, this remains the same as anywhere else on the battlefield. 1 unit per hex, usually this means 4, but can also be up to 6 for horde units. Towns can extend over several hexes, creating opportunities for several units to coordinate a cohesive defence involving several units.