I don't know what you mean by concert recordings but here are some websites for audio clips.
http://www.musicindiaonline.com/
http://www.musicalnirvana.com/index.html Click on Music Samples under the heading ‘Artists’
http://www.kannadaaudio.com/Songs/Classical/home/
http://www.malayalavedhi.com/Music/Musi … sical_____
http://as01.coolgoose.com/go/music?c=10003
http://www.udbhava.com/udbhava/albums.jsp?id=8
http://home.sprynet.com/~dsivakumar/music/intromus.htm
http://www.bhajanasampradaya.com/
http://sai.aros.net/music/karnatak/
http://www.carnaticliveconcerts.com/cgi-bin/home.cgi
http://www.rasikapriya.net/
http://www.eshakti.com Look for webcasts