Very tough question, because we donot know the outcome of the court case. RNRL won the high court case, now the same is under appeal at SC. If the case is in favour of RNRL, which the market is anticipating, then go long on RNRL, Short on RIL.
If the case is in favour of RIL, then take contra position.
or if you cannot make a guess as to the outcome of the case, then, before the judgement day, take put & Call on both RIL & RNRL, and exit immediately on news of the loosing leg, this way you can gain from the winning leg, as and when you feel happy with the profit, exit the winning leg.