Some districts are large enough to have more than one constituency also. But Jaitsar is still a village - I am sure it will be called only village by all in the serial and no mention of any nearby villages in the constituency. Jagya perhaps is standing as independent candidate (but he must be from DMK, considering the symbol allotted to him). If the people themselves want to change Heth Singh, his opponent does not need to campaign - just posters informing people that he is contesting may be enough - or is it that only a section of Jaitsar people want to change Heth Singh?
@bold, that can be the case. In real life also there are such scenarios where people believe in certain parties and continue to vote to them for years, even if the candidate is not having clean background, or is inefficient, So people in some remote villages from Jaitser constituency (I assume election is being held for Jaitser constituency) may not have any problems with HethSingh, It is also possible that HethSingh is native of some nearby village, and that village along with few surrounding villages are his permanent votebank 😆