yes
xerox copy is a valid document and can be taken as evidence .If we look into section 63 of indian evidence act,it says that " A photograph of an original is secondary evidence of its contents, though the two have not been compared,if it is proved that the thing photographed was the original."
A xerox copy is secondary source of evidence........and court willl only accept it as an valid evidence if it can be proved that the photocopy was made from the orginal.............and if it is attested by a gazzaeted officer or by a person authorized then in that case,court can take the document as an valid document.
regards,
abhishek