Hello ranganatha,
If you already know what hardware you want the simplest way is to search for it at the site address shown below and order it online.
National Instruments Products: http://www.ni.com/products/
I you are unsure on what you want and need some advise please feel free to call up one of our offices and ask for Technical Sales. Contact numbers for your local office can also be found at our website from the Contact link at the top right of the page.
Hope this is of help
Jack. W
Applications Engineer
National Instruments
