can any one inform me how early is it recommended to arrive for the comcerts??

Just depends on how good a spot you want and if the show is sold out. If you want rail get there an hour or two before doors. If you are good with 20 ft or so off rail you can show up pretty close to when doors open and end up with a pretty good spot. We just saw Sylvan Esso there (sold out), showed up right as doors opened and were maybe 100 people deep in line. Hit the potties, checked out merch, got drinks, and got a spot in the middle of the floor halfway between the stage and soundboard. Fortunately the Tabernacle always brings an awesome crowd and no matter where you end up you should have a blast. I've been late for shows there and have as much fun in the back row of a balcony as I've had on the floor.

We came after work from Knoxville (3 hrs drive) and arrived 7:30 for an 8:00 show. Parked right across the street and were in a good spot on the floor, this was for Noel Gallagher.