House Rent Allowance

Dear Experts, I would like to know about House Rent Allowance exemption against rent paid to parents, the said property is owned jointly by my parents with equal ownership. I am working in MNC, and do receive HRA from my employer. I am married and live in house which is owned by my parents. We have made 11 months rent agreements signed on Rs. 100 non judicial stamp paper and attested by notery Gazette office. I do pay rent of Rs. 8000/- pm via cheque to my parents. They understand their tax liability and ready to show proportionally in their IT return under head of income fro house property. I have a following questions with regards to above: Q1. Is it a right way to claim HRA as per income tax act? Q2. Is rent agreements on Rs. 100 stamp signed by me as tenant and my parents as owner of the house and monthly rent receipts given to me and all the rent paid to them via cheque. Are all these documents enough to show to taxman if they knock my door while auditing my return in case it happens. Please note that this rent agreement is not registered at sub registrar office as our understanding says less than 12 months agreements are not mandatory to register however these are attested by Gazette officer notary. Q3. Since my both the parents jointly own this property in equal ownership, please advise in whose name I should issue a cheque ? If I put name of both then they do not have joint account, please advise if it is necessary to open ? Some experts advise to pay them proportionally so it means Rs. 4000/- each or alternate month would be right way, please expain this doubt. Thank you very much in advance Rajesh