I'm sorry this is an image from Houzz but to give you an idea. However, you can plot on a graph paper the walls and doors of your bathroom. Then cut out other bits of paper to scale to represent the dimensions of the tub, toilet and vanity you have in mind. Now move them around to fit. It is really the best way to work out the ideal layout for your bathroom. Hope this helps

Pankaj, I just realized that initially you told us that the bathroom area was 12'-0" x 9'-0" and later you mentioned that it was 11'-8" x 8'-0". In the last floor plan, I forgot to change the bathroom with the new dimensions. Below is the floor plan with the correct dimensions for the bathroom. The bedroom is ok, I drew it 19'-2" x 12'-6". The new layout does not change the way things are placed. Everything still fit. The only difference is that the vanity is now 4'-4" long instead of 4'-8". and the toilet is closer to the shower by 1'-0". Can you give me the lengths of the walls K and L. They are the walls between the vanity and the shower area. I will send you the new layout once you give me the length of these 2 walls.

I think a comfortable distance between the island and the counter is around 42". It seems that you have only 30" between your cook top and the counter. I might be a little too tight. The wall between the entrance and the kitchen could be 4' long instead of 6', you would then be able to move the island a foot which would give you more room between the cook top and the island. Could you switch the location of the toilet and vanity in your dad's bathroom so your enter facing a vanity instead of a toilet which is a lot nicer.

Thanks a lot for your comment. I wouldn't exactly call it a walk in-closet. As you can see from the drawing, Its space provided for two single wardrobe (one on each side). Maximum width can be around 3.5 ft. The humidity point is quite relevant. The question is would it be possible to include a wet room in the space i.e. 6ft x 8.6ft. - considering I don't remove the dress wall. Wanted to get a sense on the possible layout. Thanks and look forward to your advise.