We Tenant staying in Pagadi System/Rights of Tenant

Dear Sir The Bldg is more than 50 years old (G +2) in suburb it belong to landlord. We are 04 tenants in (G+1) staying for more than 25 years in the Building premises.The Owner with her daughter lives on 2nd floor owner died in yr 2000 after that the water Bill, Asst. Tax was been transferred to his wife. We used to pay pagadi system nominal monthly rent of Rs 200 to 350/- Pm in return she used give us a receipt. In year 2008 the Landlords wife died behind living her 09 Legal Heirs of the Property (3 Sons & 06 Daughters) After that we come to know that elder son has taken rights of building (not sure about it) Owner's elder son used to collect the rent from us in return he used to give us a Rent Receipt in this name suddenly he increased the rent from 350/- to 650/- PM The other legal heirs have been objecting to property because elder son had not share any shares of the said building property to other brothers. Due to internal disputes among the brothers heirs. We Tenant are suffering internal/ external water leakage, cracks on certain external portion, staircase not in proper condition were building has not been major repaired, painted for last 10 - 15 Years which need to be Repair we continuously informing the elder son to repair external building portion etc but he never response to us on that topic Last month the BMC officers had serve notice to Occupier us U/s 353B of MMC Act to submit proforma B along with structural Audit report within 30 days failing to which legal action will be taken upon which we the 04 tenant jointly wrote letter to the elder son to take necessary steps and repair external portion in good faith of bldg as well communicate with the BMC office in reference to the notice but Elder son fail to reply to our letter. So we jointly wrote letter to BMC office that Owners Elder son had fail to reply to letter and we are not in proper situation to take decision. So kindly let us know the Terms & Condition of BMC for Tenants under Paagadi system letter dispatch to BMC Office We all 04 Tenants are ready to repair the building in good faith. Can Other legal Heirs objected to the Bldg repairs? What we need to be taken in writing from the Landlord legal Heirs? What We Tenant need to take Steps against the Owner Son Please sir advice / Suggested us on it Whether any agreement need to execute between us? What Compensation need to be taken after repair of Bldg from landlord ? Whether any Pagadi System rights policy dissolved aftr repairs ?