People in the Indian states of Assam and Kerala, and the federally administered region of Puducherry (formerly Pondicherry), are due to begin voting soon to choose their next governments in what is seen as a test for Prime Minister Narendra Modi's party.
Two more states - West Bengal and Tamil Nadu - vote later this month, with counting for all five set for 4 May.
Modi's Bharatiya Janata Party (BJP) is trying to expand beyond its traditional strongholds into regions where it has struggled to gain a foothold.
The polls are also crucial for opposition parties, which are aiming to mount a sustained challenge to the BJP's nationwide dominance.
According to India's Election Commission, the five regions have a combined 174 million voters - about 18% of the country's electorate.
