All the legislators had put in their resignations on December 29 from the Meghalaya Assembly.
The move, which came ahead of assembly polls slated next month, comes as a major blow to the ruling Congress government in the state led by Chief Minister Mukul Sangma.
The legislators joined the NPP which is an ally of the BJP-led National Democratic Alliance (NDA) at a public rally organised at Polo Fifth ground in Megahalay's capital.
The rally witnessed enormous crowd as supporters flocked to Polo ground to extend their support to their candidates for the upcoming 2018 Assembly polls.
The eight legislators who were inducted in NPP included Rowell Lyngdoh from Mawkyrwat, Sniawbhalang Dhar from Nartiang, Comingone Ymbon from Raliang, Prestone Tynsong from Pynursla, and Ngaitlang Dhar from Umroi constituency respectively, former UDP member Remington Pyngrope from Mawkynrew, and Independent candidates Hopeful Bamon from Sutnga-Saipung and Stephanson Mukhim from Amlarem also joined the party.
The party also announced the names of 50 candidates at the rally that will lock horns in the 2018 elections. (ANI)