Well Jayanta , the price of 9 Serial Port varies from company to company.

The price ranges from Rs. 850 ( $21.50) to Rs. 5000 .

Some of the best are :

1) Siig USB to 9 pin serial port ( $21.28 or Rs. 840)
2) Ithaca ,9 PIN SERIAL BOARD FOR iTHERM 280 ($40 to $55 or Rs. 1600 - 2400)

For more details , Please visit the source site :

http://www.nextag.com/9-pin-se rial-port/search-html

One more thing , without knowing the laptops configuration it would be tough to tell how you add it to your laptop.

The best option for you is to contact your laptop vendor.
They can easily tell you all the details.

Answered by Alok Gupta at 5:31 PM on May 13, 2008