What is going on with the cabinet, or is there a cabinet? Does it have doors that create a center line? Does it have an opening for a basin or is it a vessel sink basin (a bowl that sits on top of the cabinet). A picture would help us help you in the best possible way, but not having seen it- 99.9% of basins must be centered under the faucet. For splashing and for aesthetics. Exceptions are rare. Good luck! I hope to see a pic and get more specific!

did you find instructions? I find youtube to be great for this http://www.youtube.com/watch?v=p9ISDEkW3i4

For the living room, the focus should be the balcony area. So flipping the couch to face the wall and not the dining table will help. Kind of like this pic. Even if you already have the sectional that is in the diagram, you should be able to flip it. In fact a sectional would probably work better than the couch in this pic. I also really don't like the style of this pic, but it showed what I meant, For the girls' room: No matter which bedroom you choose, you should maximize floor space so that they have the biggest play space possible in their room (as they get older you can add desks for school work and such). To get this space, I would give them bunk beds. This configuration gives them an open feel and more storage, essential for girls. You posted two different kitchen designs. This makes it hard to give you advice. I agree with other posts that your sink should be away from the wall. This allows you to have stuff to the left of you (drying dishes in my house), while you wash vegetables on the right of the sink. You need the same space on both sides of the stove, also. At least 24 inches on both sides is good. 36 is better, though. The first design has a nice little countertop space that adds a place for your daughters a space to sit a watch/ talk to you while you're in the kitchen. When they added this to the first design, you lost cabinets on the other wall. This is bad, as the space is already storage limited. Try making the rounded countertop bump out into the living space more. If you play with the shape, you could make it work without losing the cabinets on the other side. It doesn't have to be rectangular or a perfect circle. You can see how this one isn't confined to the floor plan of the kitchen. I think this is what you would need to do to make it the most functional.

Where I live many municipalities have outlawed garburators in new home construction the problem is they overload the sewage treatment plants IMO they should be outlawed and people encouraged to compost food waste instead but to be honest i have no idea about India’s rules