The new charter must enable civic groups to participate in the selection of the NHRC, said the report, amid concerns charter drafters are seeking to merge the NHRC with the Ombudsman's office.
The report said any merger would mean disbanding the NHRC.
If a new human rights body is to be set up under the new charter and the government wishes to be a signatory of the ICC, it must re-apply for membership of the body, the report said.
The new body must produce its first annual human rights assessment report before being qualified to apply for membership. The process could take three years.