What are the procedures to clear a vacant land?

In your local newspaper you should find people who can do this job for you but other than that in my area there are loads of little wooden signs advertising 'land clearing services'.

As the owner, you are required by law to look after your land so that it does not have overgrown vegetation because of the problems described here. The municipality will only clear the land if a neighbour has made a complaint because your land is becoming a nuisance to them (health hazard because of mosquito, rats or dumping etc) and the municipality cannot get hold of the owner. Only then will they clear the land but they will also issue a fine of up to Rs10,000 against the owner.

In your case, you would need to find someone to do the job. From my experience, you should expect to pay Rs5000 for 80 toises of land (maybe negotiable). The municipality does not do these things for free.