Dear Mr. Manohar V.D,
Certainly, Mr. TS has correctly projected his view on Working Visa. On the contrary, if a candidate is having Student Visa and acccording to the regulation of laws for that country they should be some minimun hours dispensation to work a week. For example, in United States; F1 (Student Visa), the government and university has allowed 20 hours working in a week, sectioned OPT and CPT.
Well, all is part of the country specification. Hence suggestion is to make sure the candidate has a full idea (check with the Consulate/ Embassy) before taking any stride.