Reliance Insurance Office does not seem to have a phone number for their Indore office. At least their site fails to mention one.
Here is what you can do in this case.
* Call up 022 - 30479600. This is the phone no. of their corporate office in Mumbai. Tell them your problem and they may either directly help you or else give you the number to contact (probably in Indore or even Jabalpur, if they have a contact/liasion guy).
* Call 30338282. This is their 365 days all hours call center. I do not know whether it behaves like a local no. in all cities but you can try. Else, of course append the mumbai STD code. See if they can help.
* Write a mail to
care.rgicl@relianceada.com. This mail id is there to collect grievances and complains of customers. Write all the details including the cover note no., the cheque you issued and any and every other detail.
One of these should work.
Remember till this issue is sorted out driving your car will be illegal. The police may book you, i.e. if they catch you. And otherwise also your car is now without any protection against theft, fire, arson, accidents etc. So beware.