You may file an execution petition seeking court direction to execute the court order provided they have not preferred any appeal in this regard. 

It is necessary to peruse HC judgment to advice 

2) take out contempt of court proceedings against collector of HC order is not being complied with 

You need to file contempt if they dont follow HC judgement

If the judgment is in your favour and still the authorities are not doing anything then file a contempt application in the high court. The high court will take them to task.

Single bench has no jurisdiction to omit/declare any provision of law unconstitutional. Court may have given direction to reject/cancnel some registration of whcih are affected ?

Well, you can file contempt in HC for violating/not honoring court order.

You can file Contempt petition under section 10 in high court.

1. File execution petition in High Court for execution of orders of single bench.

2. Court will order attachment of salaries of officials not responding for executing the judgement.

Make an application under RTI Act, seeking the status of the said representation.

Based on the response / reply you receive you react, if it is not palatable, file writ before HC seeking direction against the collector and RDO by appending the earlier judgment.