Dear Sir,
In your case there can hardly be any cost of improvement as it is a piece of land. The max improvement you would have done would be the Cost of Building a Safety Wall or something.
For brokerage you would have a Bank entry proving the amount paid to the Broker, for Registration Charges you would have a bank Entry as well as the Challan Copy proving the amount paid to the registrar.
There is no such maximum limit to claim the expenses if you have actually incurred them and you have the proof.
There are a few other ways out to plan and save taxes but for that we need to understand your need and future plan in order to help you better.
Trust this clarifies your query.
Please feel free to call/ get back in case of any further clarifications.
Thanking You.
Regards,
Rohit R Sharma
BCOM, ACA, LLB-GEN, CERT. FAFP