Heat pressure cooker on medium-high heat and add oil.
Once the oil is heated, add the cumin seeds.
Once the cumin starts splattering, add the onion, ginger, and green chilis. Sautee until onions are translucent.
Add tomatoes, turmeric, salt, and red chili powder. Cook until the tomatoes soften.
Add a few tablespoons of the water and stir to combine.
Add the rajma and the water in which it was soaking. Add additional water if needed to make the total amount of water added (soaking water + additional water) 3 cups.
Add the pressure cooker lid and cook until one whistle sounds.
Lower heat to low and let cook for another 20 minutes.
Turn the heat off and allow the steam to naturally escape from the pressure cooker.
Once the lid comes off easily, remove the lid. Add garam masala and cilantro. At this point you can taste and adjust the salt as needed.