plans and photos can help us to help you better. Can you post some please?

The brick walls are very unique inside a bathroom. May I ask what country you are in and how old the house is? And I think you meant 9 feet by 6 feet, right?

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.

Hello Mr. Vkte, only a plumber can help you regarding your query on site. But one thing always remember, when you are making some changes in your bathroom tiles are going to either chip off or brake.