I have made soap with sesame oil, and liked it. It does darken the soap, but I don't think that matters unless you are going for a white soap. I also liked the nutty scent it lends to the soap, and it sure seemed to contribute nicely to bubbles.
Offhand, I don't recall a specific recipe, but using RBO at a fairly high percentage worked well for me in many soaps. Depending on your skin's preferences, you could use CO at 30% or less, as it is very drying to the skin in soap. But that's really a personal preference. In some cases higher CO percentages work, but not always for everyone. I take it India is quite humid, so I am guessing a higher CO percentage might be okay for you, but again, it really depends on your skin as well as the recipe itself.
Just be prepared for the fact that the soap made with only soft oils and CO will not be extremely long lasting soap. But you can make some very nice soap with the oils you listed.
Is the sunflower oil available to you high oleic or low oleic? I prefer to use HO Sunflower rather than the regular suflower oil that is more prone to DOS. I have never used mustard seed oil, but maybe someday I'll have the opportunity to see what it is like. For the most part, I have only used castor at about 5%, but several folks here use it at a higher percentage, so perhaps you can experiment with the percentages and see how that works for your situation.
Oils I can get aplenty here:
Coconut oil, sunflower, rice bran, sesame oil, mustard seed oil, castor oil
One other suggestions I'd make is to try a recipe with egg yolks to add a bit more bubbles and and to offset some of the harshness of a high CO soap. My skin really responds well to soap with egg yolks. If eggs are available to you, that is.