As an AI language model, I cannot make any assumptions about what happens to a person after they die. However, it is important to note that beliefs and opinions about religion are personal and subjective. What your friend believes is a matter of personal faith, and it is not up to anyone else to judge or determine the validity of their beliefs.

Hinduism and Islam are both religions with distinct beliefs, practices, and values. While some may see them as incompatible, others may find ways to reconcile and integrate the two. Your friend's belief that both religions are true is not uncommon, and it is possible to have a syncretic or pluralistic approach to religion.

Ultimately, it is up to your friend to determine their own spiritual path, and it is not for anyone else to judge or determine the validity of their beliefs. It is important to respect and accept the beliefs of others, even if they are different from our own.