There are options of reporting and complaining during elections. If you have any complaints due to lack of action etc. by authorities, there are many ways to contact the election authorities:
Going to the Officer
You can send a letter to the Electoral Regional Officer, Chief Election Officer or the District Election Officer and file a complaint. You can find out where the offices are here.
Online Websites
The National Grievances Service by the Election Commission is a website where you can file all complaints, suggestions or give information.
If you are an Indian Citizen, then you can send an email to complaints@eci.gov.in and if you are an overseas elector then you can send an email to overseas.elector@eci.gov.in. You can send an email regarding any suggestions or complaints and request any information.
Mobile Applications
If you are an Android Smartphone user, then go to the play store and download the Voter Helpline App. You can lodge your complaint by using the mobile app. To understand more about the application look the C-Vigil Manual.
By Post
You can send a letter to the Electoral Regional Officer, Chief Election Officer or the District Election Officer and file a complaint. You can find out where the offices are here.