Sanskrit is an satem indo Aryan language that evolved from proto indo european roughly 1500bc, famously the language of the rig Veda. Roughly contemporary with archaic Latin, Greek, hittite, etc.

"older" doesn't mean anything. Dravidian is its own language family with its own proto language, and sanskrit doesn't exist in a vacuum - pie dialects preceeded it (and every other ie language). It is quite likely sanskrit is related to the sintasha/andronovo migrations southward, integration with bmac/Yaz culture, and ultimately pushing dravidians farther south in India.

Sanskrit does contain a fair amount of dravidian influence (more than any other language) due to millenia of cross pollination and cultural substrata, but they are otherwise entirely unrelated languages.