I lodged a grievance but got no response by the stated date. What can we do if there is no response?

Quick answer: (1) Use the “first appeal” or escalation option on the same grievance portal — one follow-up often gets the file moving. (2) Keep your reference number and a copy of your complaint. (3) If the issue is with a local body and you got no result, you can sometimes take it to the State grievance portal (if it is a State subject). For RTI, go to the first appellate authority, then the Information Commission. See our doc on What to Do When a Civic Issue Is Not Resolved.