Welcome to the forum.
Please look at my corrections to your post and remember the rules of written English:
- Start every sentence with a capital letter.
- End every sentence with a single appropriate punctuation mark.
- Capitalise the word "I" and all proper nouns.
I don't really understand your question. Do you mean that you have been told that "I found his book inside the room" and "I found his book room" are both possible?