One of our client having google analytics 360 premium account.I written script in java for fetching a data of my website from google analytics using core reporting API v4 with proper credential. Can i use same script for google Analytics 360 for my client or is there a separate API for google analytics 360 for fetching a data from this account.
You can use your existing scripts. Google 360 has some extra API features (like an API to pull unsampled reports) but things that work with standard GA work with the commercial version, too.