Hi,
ML lenses were a series of high end lenses made by Yashica in C/Y mount for Contax and Yashica cameras from 1975 onward. They won't directly mount on the Minolta/Sony A mount and are difficult to adapt as there is less than 1mm difference in the two mounts flange distance. The only real way to do it is to have the lens mount replaced which some services do, but I have no experience of this.
EDIT: Rob beat me to it, wrote this earlier but damn internet decided that it wasn't going to work for 2 hours...