Mahsa Yazdani's 20-year-old son Mohammad Javad Zahedi was shot dead during the nationwide protests following the death of Mahsa Amini last year.
"Oru manidhan manidhanoda malatha kai aala eduthu vela seiya koodathu (No man should be asked to clear another human being's excreta for a living)" Manikandan says.
Volker Turk pleaded with states with influence to defuse the situation and stressed upholding international and humanitarian law.
India's response came after a group of UN experts raised alarm about reports of "serious human rights violations and abuses" in ethnic violence-hit Manipur.
Amnesty International's report said civilians were killed and wounded in targeted attacks. The group also reported women being raped, with some held in conditions "amounting to sexual slavery."
Earlier, Union Women and Child Development Minister Smriti Irani said she spoke to Manipur Chief Minister N Biren Singh.
Shah has asked Singh to take possible steps to nab all those involved in the incident and take appropriate actions as per law, sources said.
"My heart is full of pain and anger," he told reporters in his remarks ahead of Parliament's Monsoon Session, amid his criticism by opposition parties for not speaking on the ethnic violence.
Opposition leaders and chief ministers of states reacted to the horrific video that arose from Manipur of two Kuki women being paraded naked.
Government has told social media platforms operating in India that it is imperative for them to adhere to Indian laws. The order was given after the videom went viral triggering shock and outrage.
The Congress chief accused PM Modi of having "abdicated" his constitutional responsibility and said, "In this hour of crisis, we stand together with the people of Manipur. "
At a joint press meet after the summit, Modi brushed aside a query on allegations of human rights violations in India.