Short answer
It can help, because you share DNA, your results often illuminate a relative's, and a shared risk can prompt earlier screening for everyone, but the decision to share is entirely yours.
Many findings have implications for biological relatives, so sharing can let family members make informed choices of their own. In Indian joint families, one conversation can shift habits for three generations. That said, genetic information is personal, and some findings raise sensitive questions. Share what you choose, with whom you choose, in your own time, and a genetic counsellor can help you decide how.