I agree with divadeva. More lights. If you can add pot lights do it. If they're already there add task lighting and up the wattage on the bulbs on the pot lights (replace with LED and you can make them brighter because the wattage on LED is lower for brighter light). If you have all of that add decorative lighting. If ventilation is an issue find a way to move the air around or add air filtration. Maybe the HVAC is deficient. Maybe you can add a HEPA filter instead of the standard one that comes with the unit. Call an HVAC specialist to see if there is a way to boost air flow in the room.

Shalabh, Not sure if you know, you can search the professionals here on Houzz based on their locations. Thanks, Nitin Cornerstone Designs, Bangalore.

I disagree with the advice above, the bathroom door that is in the passage should be closed. The reason for this is that you already have a bedroom without an attached bathroom. If you go by the advice above you will then have two bedrooms without an attached bathroom. Its not ideal. Also, you havent told us for which uses are the other two bedrooms. Are there going to be old parents in the bedroom with the bathroom or kids or are you going to use this as a guest bedroom? If you close the door in the passage you can have a bigger vanity by moving the WC behind the door that is from the bedroom side. This is also good because you should never have a bathroom door with a view of the WC. The WC is a very private spot and there shouldnt be a direct view of it from the room. Also we tend to spend more time sitting on the potty than washing hands, looking at ourselves or taking a bath. Once you move the WC you can have the vanity extending till the wall and will be 2.5x bigger than what you currently have.

Just to clarify, changing the direction of the comod would give you more space outside the cubicle door. This is however considering you get a smaller tub, it would otherwise be difficult to mount. The present location of the comod seems inconvenient since it does not leave a lot of room and cannot be flipped in lieu of the column. If you can device a way around it, the plan is good. Di consider an independent, standing basin. They look good and take up lesser space. There will however be lesser and not to mention separate slab space.