To mark a stock as a collateral or view the eligible list of stock collateral, go to the funds section and click on pledge your shares for more margin. Please note that you can only pledge fully paid shares. To know the process of pledging your shares, refer the link below.
When and why is a stock under surveillance for unsolicited video?
When and why is a stock under surveillance for Information List (Unsolicited SMS)?
Should you trade in a stock under surveillance for high promoter encumbrance or non-promoter encumbrance?
Why is a stock put under surveillance for non-promoter encumbrance?