asking collector for land for purchase

A collector is not empowered to sell any land for anyone on receiving applications

If you are landless and belong to below poverty line status, you have to make approach to Tehsildar and file prescribed format application with those copies of documents required for getting such waste land belonging to the government..

There is Village Revenue Assistant in every part of the country, and he is entrusted with duty of helping citizens in drafting application and guiding them on such procedures.

Consult and engage a local lawyer.