Hello.
B VOC in MLT and BSc in MLT both are three year program but B.Voc basically focus on the technical skill of a student while BSc focus on the more academic and theoretical skills now it depends upon you that which one you will choose first ask yourself where you want to go? if you want to go in professional and technical jobs then B.voc would be a better option while if you want to see your career in academic and research work then BSc would be a better option.
Best of luck.