RethinkDB for site like moneycontrol?

So I am planning to start develop a site similar to moneycontrol, which basically pull data from stock exchange and show them in realtime. I am thinking about using RethinkDB as it is what came to close to relationalDB while pushing data to front-end instead of us polling for data.

Since I never used it, I have no idea how good it is. The application may not have much user(expecting hardly 100-500 users at max). What do you guys suggest? Will I go with RethinkDB+Java or go traditional and use websockets to poll for data. If I've made any wrong assumptions, please let me know.