I lost my old boosters

Hello @sushantnadoni and welcome to our friendly King Community. I am sorry to hear that happened to you. Unfortunately , things like lives and boosters are saved directly to your device, so if you de-install the app for whatever reason, you will lose those items and they cannot be restored. That is why we always warn players to only de-install and re-install the app as a last resort. However, the Spring Calendar event has just started which is an excellent opportunity to start saving up some boosters again.