Dear Rahanesh,
In message 4ACAEEA9.1020602@tataelxsi.co.in you wrote:
But when i type the command fw_printenv i get the following message first
"*Read error on /dev/mtd1: Success*" then u-boot environment variables are printed.
I gave up trying to reply to your questions. You supply _zero_ information. We don't know which board this is, which exact version of U-Boot you are running on it, which modifications you made to the code you are running, how you configured and built U-Boot for this board, what the MTD configuration in your Linux kernel is, nor how you set up the fw_env configuration file, etc. etc. etc.
You must not expect any help without providing essential information. I explained this to you before here: http://article.gmane.org/gmane.comp.boot-loaders.u-boot/64344 and here: http://article.gmane.org/gmane.comp.boot-loaders.u-boot/68424A and again here: http://article.gmane.org/gmane.comp.boot-loaders.u-boot/68521
All you told us was that you are running some heavily modified code based on a 5 year old version of U-Boot.
I then told you that we will not waste efforts in supporting such old code.
No matter how often you will ask the same questions again: we _cannot_ help you in this situation.
Update and use current code, please. If you cannot do this yourself, then hire someone who can. Please feel free to drop me a note when you need help with this, but note that this help will not be available for free.
Also, reading http://catb.org/esr/faqs/smart-questions.html might be beneficial to you.
Best regards,
Wolfgang Denk