How can we claim LIC insurance claim

According to law, a nominee is a trustee not the owner of the assets. In other words, he is only a caretaker of your assets. The nominee will only hold your money/asset as a trustee and will be legally bound to transfer it to the legal heirs. For most investments, a legal heir is entitled to the deceased’s assets. For instance, Section 39 of the Insurance Act says the appointed nominee will be paid, though he may not be the legal heir. The nominee, in turn, is supposed to hold the proceeds in trust and the legal heir can claim the money. Thus the wife of deceased i.e. your Sister shall be entitled to the proceeds generating out of the policy and can claim the same.