If you give gift, it should be by way of Registered Gift Deed. When you gift the property, from the date of it's Registration, you shall not be the owner of the property. Once it's the property of the children, to whom you gifted, they can do whatever they want to including mortgaging or even sale of said property.
Therefore, think before you lose control over your property.
If it is a will, Registration is better to avoid later complications, the property control shall be with you only, as long as you live.