1. do you mean the percentage of Verbal Section? If yes, then your score would fall into the range from 620 to 660 based on the assumption that your correct percentage of Verbal Section is 60% and 97% or above for Quantatitive Section. While because of GMAT is a computer adapted test (CAT) your performance plays a important role in your final score, thus making you have to try your utmost efforts to have best performance for the first 15 questions in Verbal Section.
2. You'd better to get OG E-vision