Get off at IIT Metro station & enter through the rose garden. The garden complex is linked by pathways & as you walk north west, you will eventually reach district park nursery. The other option is to get out at gate number 2 at RK Puram Metro station & leg it for almost a mile on very unpleasant sidewalks to enter through their main gate. The nursery itself is a bit overgrown but they have very helpful staff & a delightful collection of bougainvillea & Dahlias. The prices are a lot cheaper than other nurseries in the city. If you want soil, you need to bring your own sack. They do not sell pots.
Quite a few collections of plants. Very very cheap. You may not find every plant you desire but I found my monstera after looking for it in other major nurseries. My go to place for healing my plant lover soul.
It's a nice park and reasonably well kept. But it can be a lot cleaner. The toilets can also be in much better shape. There are yoga classes in the morning which are very good. Also in one corner there are morning satsangs for old people.