ok here are the details :
1. I bought 1foot long red led strip then cut it into pieces.
2. Take a cardboard pieces of same size of my tail light and paste the led strips on it
3. Then connect them with each other by wires and made two terminals +ve and -ve.
4. Remove the stock bulb and place that piece of cardboard and connect the terminals in the place of bulb.
this is the whole detail