Turn on the instant pot and press saute mode. Heat the oil and add the cumin seeds. Saute for ten seconds. Add the onion and cook for 3-4 minutes, till onion turns slightly soft.
Add the green chili, ginger and garlic and cook for 30 seconds.
Add in the tomato and cook till mushy, about 3 to 4 minutes.
Add all the Spices to the onion tomato mixture and cook till the oil slightly oozes out, about 2 to 3 minutes.
Add the soaked rajma and 3 cups of water.Give a mix and cancel the saute mode.
Close the instant pot lid and turn the vent to the sealing position. Press the manual or pressure cooker mode and cook the rajma for 30 minutes in high pressure.
Once the instant pot beeps, let the pressure release naturally.
Add ¼ teaspoon of garam masala and amchur powder (can be substituted with lemon juice).Mix the curry and add adjust the water depending on how thick or thin you prefer the rajma.. You can also mash some of the beans to make it thick. Just keep in mind that the curry thickens as it cools. Add fresh coriander leaves and Serve rajma masala with rice.