India has large number of its citizens living abroad temporarily or permanently on account of education, employment and other related reasons. These citizens were not able to participate in election process i.e. registration and voting due to the then prevailing law which required that only a citizen ordinarily resident within the territorial limits of a constituency in the country is eligible to be registered as voter in that constituency. Consequently, a huge population of citizens of India living abroad also known as non-resident Indian (NRIs) were not able to enrol themselves as voters in their home constituencies and were not able to exercise their franchise.
URL : http://eci.nic.in/eci_main1/current/NRI%20Voting_Final%20draft23012015.pdf