Complex sentence: All this turns against them when Shankars'uncle, aunt and cousin come to visit Shanlar, and Mohanlal says that he and M Nambiar's (Thilakan) daughter are in love.
Split into simpler sentences: All this turns against them when Shankars'uncle, aunty & cousin come to visit Shanlar. And Mohanlal says that he & M Nambiar's (Thilakan) daughter are in love.