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
DEPRECATEDGoogle Finance – NSE
URL - http://www.google.com/finance/info?q=NSE:AIAENG,ATULAUTO,<Add more NSE codes>
DEPRECATED Google Finance – BSE
URL -http://www.google.com/finance/info?q=BOM:524091,532683,<Add more BSE codes>
DEPRECATED Other Data Feeds (Json)
URL - http://live-nse.herokuapp.com/?symbol=AIAENG,ATULAUTO,<Add more NSE codes>
Python Utility (NSE)
URL - http://nsetools.readthedocs.org/en/latest/index.html