I went on a trip to Andamans in June of 2017. The trip was very pleasing. There was no high tides as such but sea walk was closed for the season. However there was no issue regarding scuba diving and snorkelling. We also enjoyed our beach tans and had a really great time. Hope you got the required information. If not do read my blog post for more details :) https://www.tripoto.com/trip/amazing-andamans-5b7b90cebea84
June would be too hot a month to visit. remember it's a sea side destination hence will be high on humidity. plan for October onwards when the crowds also would be lesser and weather a bit cooler than June.