Yes, you can file RTI application to Board of Higher secondary Education Delhi (BHSE) for copy of answer sheet. Board of Higher Secondary Education Delhi is an autonomous body, which is established for development of education under the guidelines of national education policy 1986 Govt. of India. and programme of action 1992 Govt. of India. It has been constituted to regulate non formal Primary, Middle, Higher Secondary (10th ), Senior Secondary (12th ) education and other vocational courses ( Under Self Employment Education Scheme) in India. Hence, it is a public Authority under section 2 (h) of the RTI Act, 2005 and application can be made to the designated PIO with requisite fees.
As per the Hon'ble Supreme Court by judgment in Central Board of Secondary Education (CBSE) Vs Aditya Bandopadhyay (2011) 11 SCR 1028, declared that all the exams, conducting bodies are bound to disclose answer sheets to the students or candidate.
For filing application for copy of exam paper please refer https://onlinerti.com/how-to-file-rti-online-for-exam