The white LED strips operate at 12 volts. They will light up even at at 9 volts but will be less brighter.
The multi-colored LEDs are not really an emergency lighting option but are good enough to help you find your way to the white ones. They also work with 9v batteries, which cost 40 rupees each. Sealed 12v batteries will cost over 800 rupees, unless you can salvage old ones from vehicles or UPSs.
It is better to use a rechargeable 9-volt batteries, which cost over 150 rupees each. They will also need a special charger. This one is called a battery multi-charger.
The LED strips come with an adhesive-coated side & a transparent plastic side. They can be cut with a knife anywhere along its length or twisted to suit your design. A slide switch or a push button and 9 volt batter clip connector may be needed.