Selling big house in Asola: Tax benefit confusion

Since last year, we've been trying to sell our big house in Asola. Kids have moved out, don't need such a huge place anymore. We're eyeing a compact 2BHK in Vasant Kunj or Greater Kailash, something manageable with good elevator access. The resale of our existing property is happening, but I'm honestly confused about capital gains tax. Heard about Section 54EC bonds and other ways to save. Has anyone here recently downsized in Delhi and used these tax benefits? Is it really straightforward or are there catches?