The seat of the deputy speaker fell vacant after T Norbu Thondok resigned from the post on March 4, a day before he was sworn in as a cabinet minister in the Kalikho Pul-led PPA government.
Assembly Speaker Wangki Lowang informed the House that Bagra was the lone candidate for the post.
Bagra, who represents Aalo West constituency in West Siang district, served as chief engineer of PHED and later as secretary, power before entering electoral politics.