If someone supported their kids in mexico in 2009 and 2010 now the kids are here and are have social security cards can I do an amendment for those years I supported them and claim them as dependents those years I supported them

No, youi cannot amend your prior years' U.S. income tax returns if the children were not living with you for a majority of the time for such years. And, I would have to check, but I believe they had to have been living in the U.S.