In Persian cooking we soak the rice for several hours in a bowl with enough water to at least cover the rice, then rinse it thoroughly until the "water runs clear". I haven't noticed much difference in the amount of water it soaks in as long as it is covered with an inch at least under water. However, the amount of water it is parboiled in makes a huge difference.
Since you mentioned basmati rice and a sympathetic disposition towards the Indian recipes, I recommend trying out the Persian rice-cooking method, though it is much more time consuming and takes long to truly master.
For this method, the amount of water isn't as precise anymore because the second stage after parboiling involves the rice being steamed, not boiled. In short, after looking the rice in a lot of water in a big pot, you immediately remove the rice when the individual pieces begin rapidly surfacing or cycling to the top. Once this occurs (around 7-10 minutes), you immediately remove the rice and strain it thoroughly under COLD water.
Here, the cooking should be halted to achieve the optimal result-and also can be calculated conservatively or taken off too soon as it will cook further when it is steamed. As the rice strains under cold water, you butter or oil the bottom of the pot and then place either thin bread or thin slices of potatoes to cover the entire bottom of the pot. This creates the "tadeek" or crusted bottom that is a huge hit to most guests. You can also omit this entirely and the Tadeek will be made anyway in the traditional way of having a crusted golden layer of rice.
Having a big pot here--or rather a pot that is correspondingly large for the amount of rice being cooked-is helpful. The rice is cooked more evenly and the timing to remove it from the heat is better estimated because the rolling of the rice to the top when it is parboiled is very easy to visualize and doesn't require as much intuition.
Then, the rice is returned to the pot and a
"mountain" is made with it-or piling the rice whereby the middle is higher. Then, make a hole in this pile with a spatula or other piercing kitchen utensil and enough water (1 cup is usually enough for 4 servings) is poured into the hole to create steam (and a little boiling) cover the pot with either a kitchen towel under the lid or a few pieces of paper towels. This is essential as it catches the steam, otherwise it will just drip from the lid back onto the rice.
Basically you need to add just enough water to create the steam that will finish cooking the rice.This should be done on medium heat so the bottom layer is not burned and is golden. This isn't a complete recipe but the major points have been added so you can decide if this method sounds suitable or worth investing in. I can share a few recipes for you if you would like. I hope this offered some insight in what you were asking.
