One possibility would be to swap the living room and the dining room. Since the current living room is larger than the current dining room you could still keep some comfortable seating (couch and upholstered chairs?) against the front wall for a keeping room/dining concept. Then your new dining areas (kitchen and dining room) and living areas (living and drawing room) would have good flow between them, which would work well both for family and entertaining. You could also add some builtin bookshelves in the drawing room or new living room to create a library area to add another fun element to the living areas. These bookshelves could be against the long walls in the drawing room, around the window with a window seat in the living room (former dining room), or built to create some separation in the open area between the drawing room and living room/stair area. Your plan seems to show some sort of builtin there, but I'm not sure what it is.

If I understand the seasons in India correctly, you have already been through the rainy season. Don't wait until the next rainy season to get the problem with your drainage fixed. Now will probably be the ideal time to get it fixed. Please get someone who will tell you what to do and then have the work done. The paint on that wall in your beautiful home will keep coming off!

What a beautiful house, Shahbaaz! I live in a similar house - a 150-year-old colonial bungalow in Kumaon. You have already received lots of excellent advice from better-qualified people, so all I would say is, keep its age and heritage character the central theme. The white tiles do clash, I am afraid ... flooring with terracotta tiles would echo the roof and look lovely. The columns and the arches over the doors and windows are amazing. But I'd say, leave it all chuna-painted - there's a beauty and softness to it. Don't let the painters add too much neel (indigo) in the limewash -- in the hills where I live, they put far too much if I don't watch out and the result is a harsh white. Natural lime has a softer, creamy look.

You're Welcome Mr. Patel :) Yes there are some plants that are better suited to indoor environment here's a guide for the same: but no plant can survive indoors indefinitely. you will need to to keep rotating them weekly or every 2 weeks. are you partial towards glass then sure it can be used. maybe paneled glass partition or a stained one like you mentioned earlier like these: The room does seem a little cluttered, which maybe because of the many different styles and no of things too. I think that can be helped by lightening the space a little and maybe bringing in a bit similarity specially the side tables and coffee tables . i have suggested the sofa upholstery color in the previous comment. shades of sage in velvet. if not then light beige in linen is also a good option. Something like in this picture https://www.houzz.in/photos/architectural-digest-india-march-april-2016-farm-house-in-delhi-phvw-vp~70030021 https://www.houzz.in/photos/vila-by-the-sea-phvw-vp~55949655 https://www.houzz.in/photos/aptes-bona-fide-expressions-phvw-vp~112062304 https://www.houzz.in/photos/sex-and-the-city-phvw-vp~94528292 https://www.houzz.in/photos/brentwood-transitional-home-phvw-vp~99412992 some bright colored cushions and an accent piece of sofa or some bright table cloth might also be good. as for curtains that will depend on the sofa upholstery you use. If you keep the same upholstery i think a nice pastel color would look better. something light. you should also choose light cushions and carpet for these sofas. and if you keep the same sofas i think you should atleast change some of the tables. I would also suggest bringing in a little more light to the room if possible. I hope this helped you. :) Best of Luck, Purva Saksena