How to recover money from a friend who is not giving the money back since last 3 years

I hope this message finds you well. I am writing to seek your expert advice and potential legal assistance in a matter pertaining to the recovery of a debt owed to me. Here are the essential details: Total Amount Lent: 7,00,000 INR Amount Recovered Till Date: 1,00,000 INR Purpose of the Loan: The money was given to a friend of my father with the understanding that he would facilitate my employment at IOCL in exchange for the funds. Transaction Trail: Trail of Transactions: I transferred a portion of the 7,00,000 INR to an account initially shared by the debtor and another portion to a different account also shared and approved by the debtor. Debtor's Assertion: The debtor is now claiming responsibility only for the funds transferred to the first account, despite having approved and instructed us to transfer funds to both accounts. Communication History: Previous Correspondence: Via multiple calls and WhatsApp Legal Questions: Given the circumstances, what legal options are available for the recovery of the entire debt? How can we establish the debtor's responsibility for both transactions, considering the approval and instructions provided by the debtor himself? Evidence and Documentation: What kind of evidence or documentation would strengthen our case, considering I don't have direct details of all the transactions as a part of the transaction was made by UPI by my friedndss and they don't have access to the screenshots right now but a few indirect transation would prove that they did make the transaction and the other part was made via cheque so that detail is available How can we ensure that the transaction trail is adequately documented for legal purposes? Potential Outcomes: What are the potential legal outcomes in a case like this? Are there any precedents or similar cases that can guide our expectations? Legal Costs and Process: What are the estimated legal costs associated with pursuing this matter? What would be the general process and timeline for legal action in a case of debt recovery?