Only after knowing the names as appearing on all documents, any definite opinion can be offered as it depends up to a large extent as to what kinds of variations are there. Are the names appearing in various documents altogether totally different or there is only minor spelling variation like in the case of 's' and 'sh'. Also is only surname is missing in one document though the same is appearing on other documents. Merely to say that there is variation in the names in various documents is a very vague statement. In case of variation of a very minute nature, it may not cause any problem during the process of document verification which depends on the attitude of the concerned official also who is verifying the documents. In my opinion the author should show his all original document to a local known and reliable lawyer for further advice.