You can file RTI to obtain Certified Copy / Copies of the Mother Deed under Section 2 (j) of the RTI Act .
You can file RTI Application to the concerned Sub-Registrar Office or Tahsildar Office where the Deed was executed / registered as per The Indian Registration (Himachal Pradesh Amendment) Act 1968. The Sub-Registrar Office or Tahsildar Office under the Revenue Department of Himachal Pardesh are "Public Authorities" as per Section 2 (h) of the RTI Act.
To know further about the procedure to apply RTI Applications, please visit https://onlinerti.com/