What to do in case of mental harassment case against parents in India?

Yes, you can sue or criminally complain against parents for mental harassment, but the remedy depends on facts: if you are a woman in a domestic relationship you may seek civil relief (protection orders, residence, maintenance, compensation) under the Protection of Women from Domestic Violence Act, 2005 [https://www.indiacode.nic.in/handle/123456789/2021]. Criminal offences such as intimidation, insult, stalking or other offences are now defined in the Bharatiya Nyaya Sanhita, 2023 and must be prosecuted under its provisions; procedure to register complaints, FIRs and investigations is governed by the Bharatiya Nagarik Suraksha Sanhita, 2023 while evidentiary rules fall under the Bharatiya Sakshya Adhiniyam, 2023. [BNS: https://www.indiacode.nic.in/handle/123456789/21069] [BNSS: https://www.indiacode.nic.in/handle/123456789/20099] [BSA: https://www.indiacode.nic.in/handle/123456789/21070]. A writ under Article 226 is typically available against the State or against a private body only when it performs a public function or the impugned act involves a public law element (see Pradeep Kumar Biswas v. Indian Institute of Chemical Biology, 2002; St. Mary's Education Society v. Rajendra Prasad Bhargava, 2023). [https://indiankanoon.org/doc/471272/] [https://indiankanoon.org/doc/167605589/] If your parents are private individuals a High Court writ directly against them is usually not maintainable, but you can file criminal complaints or civil/domestic-violence petitions and you may file a writ against State authorities (for example for police inaction) if they fail to protect your rights (see Nilabati Behera v. State of Orissa, 1993). [https://indiankanoon.org/doc/1628260/]