All broadband connections through phones in the name of serving / retired, state / central / PSU employees are eligible for 20 % discount on usage and rental. You need to collect an application from exchange, get it signed by your head of department and give it back to exchange. From the next bill you will get 20% off on rent and extra usage (if any). I think you are mentioning Home Combo 500 as Home 500 has been discontinued. For Home 500 plan, you will get Rs. 100 off and you need to pay only Rs. 400 + 10.3 % tax.I think it is better to opt Home Combo 600 which gives 2.5 GB day time usage than Home Combo 500 which gives 1.5 GB day time usage.