No citizen shall be discriminated against on the grounds of race, religion, language, caste, sex, political opinion, place of birth or any one of such grounds: Provided that it shall be lawful to require a person to acquire within a reasonable time sufficient knowledge of any language as a qualification for any employment or office in the Public, Judicial or Local Government Service or in the service of any Public Corporation, where such knowledge is reasonably necessary for the discharge of the duties of such employment or office: Provided further that it shall be lawful to require a person to have a sufficient knowledge of any language as a qualification for any such employment or office where no function of that employment or office can be discharged otherwise than with a knowledge of that language.