Am a us citizen,same my brother.My mother live overseas and sold a property.I got 13.500 and my brother too.mothet kept the rest.But after 25 years since my father die we were told that my mother did put us on the tittle.Idont know if that was a requirement from my country or what.I never see the title.So how can I treat this? As a gift,am retired on SS I don't have to file income taxes.thank yoi

Your question is a little confusing. Did your mother sell the house and then send you $13.5K as a gift? Or had your mother gifted you part ownership of the house and your portion of the proceeds from the sale was $13.5K? It makes a difference. Assuming that you were a part owner along with your mother and brother then you must report the sale and your portions of the proceeds and cost basis on Schedule D of your income tax return. Your cost basis depends on the fraction of your ownership and what your mother's original cost basis was.

Your question is a little confusing. Did your mother sell the house and then send you $13.5K as a gift? Or had your mother gifted you part ownership of the house and your portion of the proceeds from the sale was $13.5K? It makes a difference. Assuming that you were a part owner along with your mother and brother then you must report the sale and your portions of the proceeds and cost basis on Schedule D of your income tax return. Your cost basis depends on the fraction of your ownership and what your mother's original cost basis was.
Well,she sold the house and after all the expenses,she told me here is what I want to share with you.and gave me13.500 in cash.she kept 50% of the money and the other 50% I share with my brother.I have no knowledge on anything else. I have never see the title or any document from the house I didn't know I was in the title.

Since you know nothing about ever being a part owner (despite the subject of this thread being "I sold a property") this appears to be a simple gift of cash from your mother. As the recipient of a gift you have no US tax consequences at all.

The money is either a GIFT or an INHERITANCE.

In either case, it is NOT subject to U.S. income taxes.

There is NO federal inheritance tax, and the amounts cited are so small that there is NO estate tax issues.

There MAY be a state inheritance or gift tax issue, but that is not likely.