Tax implications of MUTUAL FUND REDEMPTION

Refer this link. https://cleartax.in/s/different-mutual-funds-taxed

The date & amount of investment and redemtion can be obtained through bank statement since bank is the only channel. Based on that the nature of tax whether long term / short term can be determined and taxed accordingly.  

It should have been done through bank only in any case, so its better you analyse the bank statement to identfy the date and amount.  If not possible, you can approach the MF management company and quote the PAN of the client with which they might be able to help in you with the details.