I'd suggest a shallow bench underneath the window and flank the windows with a base cabinet on one side and a desk on the other. Then open book shelves above the base cabinet and desk. I can't tell what the dark wall is on the one end. The steps need to curve from the door to the wall. A smallish sofa would be great for viewing a flat screne TV and a square table and 3 chairs up against the dark wall would be a great place for puzzles and games. Put a pendant over the table.

white will go well r u can go with same colour as the wall

most colours would go with the light to neutral oak floor. A dark contrast wood panelled door would look great. someone here said that should be avoided. I feel a dark contrast,whether in wood, or a coloured paint would work very well. A painted panelled door (red, blue, green etc) with a wooden floor wood be a bold choice and will give the space a more European look.

We are looking for interior designer nearby Noida who can just guide us by making 3D model of our flat.