Internet light not blinking in i Ball ADSL +2 router

[RakeshM]

1.My bill was rs.2700 .I was using bb home combo uld rs.675 for 1st time ,so my bill should be rs.2700?All things including landline ,routerand plan was given 1 month before.

Nope. Your very 1st broadband bill includes 1 month security deposit, installation charges, BB fixed charge on pro rata basis over the billed month, etc... check detailed explanation here: BSNL Bills!! | BSNL Broadband | India Broadband Forum

Your 2nd bill should be:
675 + Landline usage charges if any + taxes on (675 + Landline usage charges if any)

2.How to check my usage of internet?

* selfcare.sdc.bsnl.co.in for South Zone (Andhra Pradesh, Chennai, Karnataka, Kerala, Tamilnadu) customers
* selfcare.ndc.bsnl.co.in for North Zone (Haryana, Punjab, UP(West), UP(East), Himachal Pradesh, Rajasthan, Jammu & Kashmir) customers
* selfcare.wdc.bsnl.co.in for West Zone (Maharashtra, Madhya Pradesh, Chattishgarh, Gujarat ) customers
* selfcare.edc.bsnl.co.in for East Zone (Kolkata, Orissa, Bihar, West Bengal, Adman Nicobar, Assam, Jharkhand, North East ) customers

Check: BSNL Broadband Data Usage Checking Process through Online Portal and SMS

You need to register on one of the above portals corresponding to the zone you fall under... Be careful while registering as it's a one time process...