in a concurrent audit, you select transactions on a sample basis and based on that you report your findings in the Long form audit report (LFAR).
So when you select a particular transaction, do a 'walkthrough' for that sample. right from it's initiation to completion.
FIrst check, if the RTGS request is valid, if it is by the appropriate authority, is it within his powers to transfer the said amount.
Then, check for clearing aspect of the transactio, if it was settled in the same settlement session (RTGS transactions have 3 settlement sessions daily, except Sat 2 sessions & Sun)
And finally check if, the corresponding entry has been reflected in the account on the same day, after settlement. (This step is important when it comes to ascertaining the correct closing balance)