TicketGoose.com is a very good website for booking bus ticket online.
It’s product and product category page gives real time stat and useful information to customers when compared to competitors.
Here below pages for your reference.
https://ticketgoose.com/bus-tickets/chennai
https://ticketgoose.com/bus-tickets/chennai-to-madurai
https://ticketgoose.com/kpn-travels