When did the Greeks and Romans first travel to India and what they did after first traveling there?
Alexander the Great conquered part of India. That was considered to be the end of the world to them. Sanskrit is much older than Greece. It seems that they shared a common origin because they are called Indoeuropean langauages. The Romans just had trade because their empire never extended to India. There were outposts because the Romans eventually conquered much of of the Ptolemaic empire. Sanskrit is too old to have been established by Romans or Greeks in historic times. I don’t think anyone really knows how they came to share the same apparent root language. It was likely about 8,500 years ago when the Indoeuropean languages diverged from the common origin. That sounds reasonable but I don’t know how accurate it is.