With the mount i listed below. you can have your Novatac positioned in 5 positions. to the side would be good as you could press the tailcap with your support hand.
or you can get straight under mounts from CAA. The only thing though is that you need to think about ergonomics. how will you turn on the light and access the light etc. also you need to think about how you intend to holster the light with the rail on the weapon and with the light.
Also you might want to get the CAA belt rail clip. it allows you to attach Insight M3 style lights or any picatinny mount to the belt clip. Also it can rotate.