Union home minister Rajnath Singh, BJP president Amit Shah, Arunachal Pradesh chief minister Pema Khandu, Manipur CM N. Biren Singh, Assam chief minister Sarbananda Sonowal and designated Nagaland chief minister Neiphiu Rio among others were present at the swearing-in ceremony in the lawns of the Raj Bhavan.
Outgoing chief minister Mukul Sangma said, "I wish the new team my best wishes and I hope they do justice to the people and the state befitting to the expectations and aspirations of those who have given them the mandate".
"We are committed to strengthening our party across the North East and to winning back the trust of the people", Gandhi said.
"A pre-poll alliance was forged between the UDP and HSPDP but they (UDP) did not consult us when they proposed the name of Conrad Sangma to be the Chief Minister", HSPDP President Ardent Basaiawmoit told journalists. He was also the Meghalaya chief minister from 1988 to 1990.
40-year-old Conard Sangma will be heading a five-party coalition, including the Bharatiya Janata Party (BJP), in the northeastern state.
Despite a fractured mandate in the Assembly polls, the state is going to witness its first non-Congress government taking charge in 15 years.
Shillong: Having entered politics at an early age in the shadow of his father, Conrad K Sangma has come into his own after successfully leading his party NPP in Meghalaya Assembly elections and uniting regional outfits against the Congress.
Cornard Sangma, the newly sworn in Chief Minister of Meghalaya is known for his capabilities and efficiency.
He also used the hashtag "DemocracyDemonetised" with his tweet to target the BJP.
The Modi-led BJP government has increased the number of states it rules independently or in coalitions nearly fourfold since it came to power in 2014. Meghalaya CM Conrad Sangma is also the youngest son of former Lok Sabha speaker PA Sangma.
On Sunday, Sangma staked a claim to form the Meghalaya Democratic Alliance (MDA) government with the support of six from UDP, four from People's Democratic Front (PDF), two each from HSPDP and BJP, besides one Independent MLA, Samuel Sangma.