Indian real-estate websites PropTiger.com and Housing.com are merging to create the country’s top portal for residential listings and property services, as Rupert Murdoch’s News Corp. boosts its investment in the growing sector while Masayoshi Son’s SoftBank Group Corp. scales back. REA Group Ltd., an Australian real-estate company controlled by News Corp., is putting $50 million into the new joint entity, while a SoftBank-owned affiliate is investing $5 million.