Landlord asking to vacate property after agreeing to extend lease

Hi, I am from Bangalore. I am staying as a tenant in the same house for last three years in an appartment complex. My lease is set to expire on 1st December 2024. I recently bought house nearby which is getting renovated and will be ready by 1st February 2025. I had informed and requested and my landlord in July 2024 over whatsapp that I would need to continue staying in the apartment for three months after our lease expired in Dec 2024 and he had said 'This should not be a problem. Let me check with my wife and confirm". After this message exchange I was under the impression that I can stay here till March 2025 and then straight away move to my own house. However suddenly in end September my landlord said he can't extend lease and wants me to vacate by 1st Dec. He says he plans to sell the house and hence I must vacate as soon as my lease is over. I have a three year old and my wife has medical issues so moving houses for three months will be a major stress for us. Is there anything I can do to not move house for three months? Had he not said "it should not be a problem...."in July 2024, i would have speeded up renovation and finished by December 2024 but now there is no chance that renovation for new house will end before march 2025. Do I have any legal right to extend my stay for three months? I have paid rent on time always and also given 6 month rent as deposit. My agreement also has an arbitration clause in case of any disputes. Plz advice