TS = Total Science. This score is determined by your raw score, the total number of questions you answered correctly, in General Chemistry, Biology, Physics, and Organic Chemistry. For example, if you answered 20 questions correctly in Biology, 15 in General Chemistry, 15 in Organic Chemistry, and 20 in Physics, your Total Science raw score would be 20+15+15+20, or 70. A 70 raw score corresponds to a 300 for Total Science.
AA = Academic Average. This is the average of the standard scores (not raw scores) you received for all of the sections.
If you have the official OAT guide, it shows you how these figures are determined.
Schools will receive the individual section scores (Chemistry, Biology, Organic Chemistry, Physics, Quantitative Reasoning, Reading Comprehension) as well as your Academic Average and Total Science scores.
Hope this helps!