House Owner not returning my lease amount 5.25 lakhs

We were staying in a leased 1bhk in Bangalore at Basveshwaranagar. Lease amount is 5.25 lakhs for a duration of 3 years. Period starting ( 1/11/2014 to 31/10/2017) but due to my transfer I need to move Hyderabad & i have informed my owner orally on 02/ 04/ 2015, That as per agreement I need to inform you three months before vacating the house so I’ll be vacating the house on 10/07/2015 so please make arrangements. He dint returned a single paisa by july & I was in a hurry to rush to Hyderabad so I vacated the house & owner told me by Oct- 2015 he will return, but for my surprise when I came back in oct-2015 he told me he has sold the building & your amount is with new owner & he introduced him & the new owner agreed he will return in one month time, but till now he dint return my amount. He is keep on postponing the dates. He dint sign & gave me the new agreement paper also. The new agreement paper was prepared by me & given to him two months back. Question - what legal action I can take? Which owner is responsible now to return back my amount ? On whom i need to take legal action ? Please help me to get my amount back ?