The activist, V Mahendran, from Pethuparai near Kodaikanal filed a petition in the office against Sharmila's proposed marriage with Desmond Coutinho, a British national.
He contended that if the couple was granted permission, they would settle in Kodaikanal permanently and this was not good for the interests of local residents and the safety of the place.
In his plea filed with the Sub-Registrar at Kodaikanal, he said Mr Coutinho was in charge of a website, engaged in activities around the world, and their stay here would affect peace in the hill station.
The Sub-Registrar had called for objections under the Special Marriage Act between Ms Sharmila and the British national as they belonged to different nations and different religions.
Irom Sharmila had moved to the hill town with Mr Coutinho following her defeat in the Manipur state assembly elections last March and her party 'People's Resurgence and Justice Alliance' had suffered a rout.
The 44-year-old shot to fame after she launched her fast-unto-death on November 4, 2000, demanding the withdrawal of Armed Forces (Special Powers) Act, 1958 from Manipur.
Ms Sharmila, also known as 'Iron Lady', broke her 16-year-long hunger strike, the world's longest, on August 9, 2016 and declared she wanted to become the chief minister so that she could repeal the contentious AFSPA.