You can easily drop a year in RMLNLU for NLSIU or NALSAR. The academic calendar at RMLNLU is completely different and not so tight. There are no mid-semester exams and only end-semester exams take place.
It is not mandatory to take part in moots, debates, and mediation competitions. You can score well in your semester-end exams by studying 2 weeks before them and can easily devote time and prepare for CLAT.
Thus we can conclude that it is just a myth among people who think that they will not get time after getting admission to RMLNLU. So remove this myth from your mind and start preparing for the exam.