Jr. NTR sported long hair, short hair, rings, big moustache, clean shave, long heard and even traditional brahmin hair-do, for his various roles in different films. He never tonsured his head for any role, till date.
The actor might go for such look in RRR. For a brief period of time, the character Komaram Bheem in the film could spend time in British prison and there his head could be tonsured it seems.
Also, the character will meet Ram Charan's Alluri Seetharamaraju character in the film, at the prison, it seems. The prison escape and moments after that, lead for them to take inspiration from each other, it seems.
This is all fiction added to the historical facts of both legendary Telugu freedom fighters. Rajamouli wants to use his Baahubali stardom to tell such an emotional story about the two legends that youngsters will seek to learn more about them in future.
As off now, these can only be taken as speculations from our sources and not 100% truth. Because no one can say what Rajamouli would ultimately think works in his film!