Wikipedia
Rigwnai is a wrap-around worn by Tripuri women.
Rigwnai (also known as Pachhra in Bengali and Pon in Halam-Kuki) is the traditional dress of Tripuri women, the indegineous inhabitants of Tripura, similar to those of other tribal communities in other north-eastern Indian states of Assam, Manipur, Meghalaya, Mizoram etc. It is worn by wrapping it around the waist. Sometimes it is also worn with "Risa" which is a piece of cloth wrapped around the bust region. It is mostly worn by the "debbarma" tribals and also by other tribals in Tripura. A similar kind of the Rigwnai is also worn by Manipuris and Mizos.
The most common kind of Rigwnai worn by the Tripuri women is called the "Chamathwi bar" and comprises white cloth bordered by maroon or other colors. The "Chamathwi bar" is worn during various important occasions like wedding ceremonies etc. and festivals like Goria Puja and Hangrai.