Depends on what the RAT drives.
On the L1011, is supplies hydraulic pressure/flow, and as I recall, there is no limit on its use.
Of course, if it is used, it needs to be properly stowed later on as it is a drag item.
No 'special' inspection as I recall after use, just a new squib fitted.
During heavy maintenance checks it is, of course, inspected.
Only used it once...worked just as designed.