My car won't go into any gear it's locked out and when it was driving before I had to stop due to the banging when in gear 1 2 3 4 5 .... I'm pretty sure it's the gear box .. The bang was a very disturbing noise , even Rollin back in N it was on banging round .... Is this def my transmission ? Please help me out here with either parts of advice

 

You may have:
1) Thrown the clutch out
2) Have transmission failure
3) Popped a drive shaft or CV joint