Hello Kusum, It's very difficult to imagine your hall with this brief description , would it be possible to share the floor plan and photos. Thanks, Nitin. CORNERSTONE DESIGNS

Regular window size 4width X 4 height floor to window sill 3' kitchen window size 4 width X 3 height floor to window sill 4' if low sill means stove burner of due to air

If you're looking for a cheaper and more flexible option,dark royal color curtains/as suitable with rest of design with a stylish curtain rod can look good and hide your kitchen as well. Sleek Flexible furniture that double up as breakfast tables can be paired there too. Decorating them sith vase/plants can give good look overall. In case of traditional interiors , local wall hanging of the right size could work perfectly

Hi Shivam, I hope you are doing good. There is no particular tile size that may look good as it completely depend kind of design you have in your perspective. If you are looking at more traditional interiors then generally smaller tiles with motifs or emblems look good which have a representative geometrical or floral patterns. If you are looking at more modern interiors then generally bigger tile sizes are preferred for clean look less joints.  Regards, deSigneR