Mutual Fund schemes usually don’t have a maturity date unless you have invested in a close-ended ELSS or other close-ended schemes like FMPs. Even in case of a SIP, there is a term for which investments need to be made regularly. If the investor passes away while the SIP term is on or before the maturity of a close-ended scheme, there are defined procedures to be followed by the nominee, survivors in case of joint holding or legal heirs to claim the proceeds. This process is called transmission. For someone to request for a transmission, the person must be aware of your Mutual Fund investments in the first place, else it can just remain unclaimed forever.
Hence, it is advisable to always add a nominee to your Mutual Fund investments just like any other investments and keep the nominee informed about it. If you have a joint account holding, the survivors mentioned in your account can claim for transmission. But if you have neither got nominees nor surviving joint holders mentioned in your folio, your legal heirs can still request for transmission by submitting all the necessary documents and proofs including a death certificate. The person requesting for transmission needs to be KYC registered.