Probably not the brightest question to ask at your stage 1 selection.
Hello NATS I'd like to come and work for you but are there any bail out options if I'm a bit rubbish?
Oh and please spend £x000 training me cheers.
The answer to your question is broadly no.
Most non NATS units train from their assistant ranks or recruit those who pass the NATS course but don't validate at their unit.
A possible option is eurocontrol but chances are if you don't get in with NATS then you will have similar issues with them.
You can of course reapply to NATS after a year (I think) or you may have to accept that you might just not have the aptitude to be an ATCO. Not many do but good luck.
And lets have a bit more of a positive mental attitude eh?