Taking back money given to someone.

Hi, I would like to get a proper advice on below instances. On September- November 2018, I was planning tto take loan of 1,80000/- when I was working in a startup. The director of company was partners. Partner 1 n partner 2 Mr. Z. The company was going in debt. When Mr. Z came to know that I was applying for loan he insisted that you should take loan of 4 lacks. Till then their company was shut down n Mr. Z had new plan n wanted me to work as partner in it. Mr. Z put his all bank contact on work n I got loan of 4 lacks. The planning was to pay the complete loan through new firm we were going to start. But everything didn't go as planned as there was no revenue n many EMI bounced. As of March 2020, I decided to step down from partnership n told Mr. Z to pay his part taken from loan. For 4 lacks loan taken I had spend 1.15 lacks Mr. Z 2.15 lacks n rest was spend on establishing new company. Still the outstanding amount is 3.30 lacks. As per mutual concent I'm paying my part with the pre closure interest n he is paying his part with emi of 4 months. Due to covid we could not make a legal document of above. As I don't want to chase Mr. Z for money. I had told him that we would make pointers on how you would pay me in installment in a Stam paper n notarized it. I would like to get proper advice in this.