Check the following they are free, they generate Json, though for different exchanges you need to ensure that correct syntax is used. even Yahoo finance works well, but it has some issues regarding NSE and BSE data, which is always generated Null
DEPRECATED
Google Finance - NSE
URL - http://www.google.com/finance/info?q=NSE:AIAENG,ATULAUTO,
DEPRECATED
Google Finance - BSE
URL -http://www.google.com/finance/info?q=BOM:524091,532683,
DEPRECATED
Other Data Feeds (Json)
URL - http://live-nse.herokuapp.com/?symbol=AIAENG,ATULAUTO,
Python Utility (NSE)
URL - http://nsetools.readthedocs.org/en/latest/index.html