Wiki says 'After his death, his brother Tirunarayanan chronicled Ramanujan's remaining handwritten notes consisting of formulae on singular moduli, hypergeometric series and continued fractions and compiled them' (quoted from Indian express (I would trust not much outside The Hindu but still) and 'When Ramanujan was a year and a half old, his mother gave birth to a son, Sadagopan, who died less than three months later'. On this site 'His mother gave birth to several children after Ramanujan, but none of them survived infancy' is written. As far as I know the local folklore is Ramanujan or his immediate family had no direct descendants.
Did Srinivasa Ramanujan have a surviving sibling?