1. I was told Delhi has new Rent act where Tenant defaults the rent he will have to vacate the house in 1 month. is this applicable for Mohali ( SAS Nagar ) also as it comes in Punjab.The Delhi rental act will be applicable to Delhi alone, the rental or tenancy rights mentioned to you by lawyers here are common and it is applicable in Punjab too with their own modifications in some aspects, a local lawyer from Punjab will be able to explain you properly about the differences between the local law and other state law in this regard.
2. If i am sending legal notice , will he have to submit the rent in court or give it me.
He is liable to pay you only, but if you refuse to receive the rent, he may deposit the same with the court.
3. What if he doesnt accept the legal notice.
File an eviction suit based on his refusal to receive the notice.
4. Also if i file a case. he doesnt give any rent or vacate the house till the time verdict comes as it may take months.
Since you have taken legal recourse you may have to go by the court proceedings only, what solution do you expect for your this question?
5. The house is under my mother's name who is a senior citizen. Can this help in any way.
All are equal before law, senior citizen status will not attract sympathy from the court.