F5 BIGIP & LTM configuration best practice/hardening guide or any tool to check whether configuration of BIG-IP & LTM.

Yes, there is a reference guide available at [http://iase.disa.mil/stigs/net_perimeter/network-infrastructure/Pages/other.aspx]. Security Technical Implementation Guides (STIGs) are published by the US military to promote hardening. The page is publicly accessible.

After unzipping, find the XML file and open it in a browser that supports XML viewing. You will see segmented rule titles that clarify vulnerability to evaluate for, procedure to check for content and how to fix/harden the gap if necessary.