Estate Law Questions? Ask an Estate Lawyer.
Can you take a look at the title and tell me if its says that the condo is jointly owned by the trust and your mother? I think that is what you are saying; but I am not sure...
Also, who is the executor of your mother's estate?
Since the condo is an asset of the trust and your brother is now the trustee, you brother has to look to the terms of the trust to see what happens to the condo and when. The trust may or may provide for a transfer of the condo at this time. But, for example, if we assume that under the terms of the trust the condo was to given to equally to you and your brother upon your mother passing away, then your brother would first have to transfer title from the trust to you and him as joint beneficiaries.
To transfer property to the name of the successor trustee, a form called "Affidavit of Death of Trustee" should be prepared and filed with the real property recording office in the county where the property is located. Once that is done [and unless the terms of the trust indicate otherwise], then your brother can transfer title to all four children equally who can then agree or not agree to sell it and divide the proceeds.
You are welcome.