Nagar Panchayat Status: Nagar Panchayats may be considered urban or rural for LTCG purposes based on criteria like population and development. The exact classification under the Income Tax Act depends on additional factors.
Rural Classification Criteria: Either population size or distance from an urban center can classify land as rural for LTCG purposes, not necessarily both.
Authority for Documentation: The classification is typically determined by the Revenue Department or District Collector. Formal documentation, such as a certificate, can be obtained from them, even though it may not be part of standard property documents like the 7/12 extract.
Given your situation and the complexities involved, consulting with a professional is recommended. You can also consider taking my advice for a detailed analysis and assistance in navigating these requirements.