The notification was issued by President Pranab Mukherjee.
Tezpur, Kaliabor, Jorhat, Dibrugarh and Lakhimpur seats in Assam, and Tripura (West) constituency will go for polls on April 7.
While March 21 is the last date for filing nominations, scrutiny of the papers will be held the next day. Candidates in these constituencies can withdraw nominations by March 24.
The polling hours have been fixed as 7 AM to 5 PM.
Saturday, March 15, will see issue of notifications for 93 constituencies spread across 18 states going to polls on April 9 and 10.
The nine-phased polling exercise will end on May 12 and counting of votes will be held on May 16.