I see a few contradictory statements in your post.
" I am the only official heir. yet, the deceased left some agreements to give some of his properties to someone else"
Does it state this in the Last Will & Testament, or in legally recognized attachments to the Will of the deceased? If so, then you are NOT the only heir, regardless of what you may have been told, or assumed.
Have you already filed the Last Will & Testament in a court of law for probate?
Are you the "legally" recognized administrator of the estate, that is recognized and/or appointed as such by a court of law?
Have you established the estate, obtained an EIN for that estate?
Have all assets of the deceased, including the rental properties been transferred from ownership by the deceased, to the estate?
