Hello @Reddy Pramodh Welcome to Atlassian Community!
On top of @Sebastian Krzewiński's comment, you can also download the jar installer directly from the following repository:
Regards,
Eduardo Alvarenga
Atlassian Support APAC
@Reddy Pramodh you have to download the same version as your Bamboo Server. Please read the link provided by @Sebastian Krzewiński for more installation instructions.