Yes, you can file RTI Applications for Copy of your Answer Copy from Himachal Pradesh Public Service Commission (HPPSC).
HPPSC is an independent and impartial Constitutional Authority, set up under Article 315 of the Constitution of India to discharge the duties and functions , assigned to them under Article 320 of the Constitution. The Commission consists of a Chairman and three Members. The terms and conditions of service of Chairman and Members of the Commission are being governed under the State Public Service Commission (MEMBER) Regulations, 1971. HPPSC is a "Public Authority" as per Section 2 (h) of the RTI Act 2005 and comes under its ambit.
You can file RTI to obtain Certified Copies of your Answer / OMR Sheets under Section 2 (j) of the RTI Act from HPPSC by addressing the same to the designated "Public Information Officer (PIO)" through Registered Post and by paying the prescribed fee. You should attach a Copy of your Admit Card and mention your Roll No., Registration No., Name of the Exam clearly in the Application.
To know more about the procedure to file RTI Application for Copies of Answer / OMR Sheets, please refer https://onlinerti.com/how-to-file-rti-online-for-exam