Nationalist Democratic Progressive Party (NDPP)'s Neiphiu Rio and National People's Party (NPP)'s Conrad Sangma will be sworn in as chief ministers of Nagaland and Meghalaya respectively today.
BJP's Manik Saha, will take oath as the chief minister of the saffron-party led alliance government in Tripura on Thursday, a day after Holi.
Prime Minister Narendra Modi and Union Home Minister Amit Shah are expected to attend all three ceremonies this week.
Rio will be leading an all-party government with no opposition in his state even as the central government continues talks with former rebels of the NSCN (IM) to finalise a long-awaited peace accord in the border state.
The NDPP-BJP coalition, in the recently concluded Nagaland polls, won 37 seats in the 60-member Assembly.
All other parties in the state subsequently extended their letters of support to the Rio-led alliance.
Since the commencement of election campaign, both NDPP and BJP had projected 72-year-old Rio as their chief ministerial candidate.
In Meghalaya, the NPP-led alliance, with 45 MLAs in its support including two of the BJP, has staked claim to form government.
NPP head Conrad K Sangma, whose party won 26 seats in the February 27 elections, will take oath as the chief minister on Tuesday, along with other cabinet ministers.
On Monday, 58 newly elected MLAs were sworn in as members of the assembly with pro-tem speaker Timothy D Shira administering the oath of office and secrecy to them.
Sangma, who will be sworn in as the chief minister for a second consecutive term, was also present at the ceremony.
The speaker of the newly formed assembly will be elected on March 9 during a special House session.
The BJP in Tripura stated that its leader Manik Saha will continue to hold the post of the chief minister.
Saha was named as the chief minister at a meeting of the BJP legislature party in Agartala on Monday.
In the recently held elections, the BJP won 32 seats in the 60-member Assembly, while its ally- Indigenous People's Front of Tripura (IPFT), won one seat.
Talking to reporters outside Raj Bhavan, BJP state president Rajib Bhattacharjee said, "Manik Saha, who was unanimously elected as the legislature party leader today, met the governor and staked claim to form government. Our ally, IPFT, has also extended its letter of support." The BJP and its allies have retained power in Tripura and Nagaland, while in Meghalaya, the National People's Party (NPP) emerged as the single largest party, with the saffron party later extending support to the regional outfit led by Conrad Sangma.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)