Sathi haru kayak.com bata nepal janako lagi ticket ok garda redress number (7 digit) bhanxa..k hamile kayak.com bata ticket ok garda redress number halnai parxa ho ra.. its urgent can anybody reply my question 

No it's optional. Happy travels.

Are you sure broo

Travelers without Redress Control Numbers
Not everyone has a redress number.
If you don't have a redress number and an airline or a travel site asks for your redress number, you can leave it blank.

https://www.dhs.gov/redress-control-numbers

The Redress Control Number is the record identifier for people who apply for redress through the DHS Travel Redress Inquiry Program (DHS TRIP). DHS TRIP is for travelers who have been repeatedly identified for additional screening and who want to file an inquiry to have erroneous information corrected in DHS systems.

Airlines will modify their reservations systems to allow passengers who have a 7-digit redress number to enter it when making their reservation.

Travelers without Redress Control Numbers
Not everyone has a redress number.
If you don't have a redress number and an airline or a travel site asks for your redress number, you can leave it blank.
If you do not have a redress number, you will still be able to make reservations and travel as normal. The redress number is an optional field and is not relevant for most travelers.

From DHS website

Thank you so much maxpayne and s001. Appreciated