Mr. Raj the basic requirement is there must be a need not merely a desire.
for every state the interpretation of rent law is different reason being the rent laws differ from state to state.
even while filing petition various necessary ingredients are required to be mentioned carefully.
ur mother must be in position to prove her need...i.e. why she requires the premises?...how may properties she is having? etc......all such issues can be better explained by a local lawyer.
some one can appear as Attorney on behalf of ur mother, but when it comes to the answering of questions which are strictly out of personal knowledge of ur mother then she is supposed to be there in the court.
better would be u meet some local lawyer, i think u ve posted various queries here in this context.....we dont mind answering to them......but a personal consultation gives u a better idea of what the actual position of law is.