Hi Thanks. I now tried with the 2nd IP and it worked. 
Due to some reasons it doesn't like the 1st IP, which works fine for GUI access. But it worked with 2nd IP. We actually have three IPs for this FS7300.
Now, on the 2nd part - How to add it to Storage Insights. Note: The SI is existing one and has a A9000R being monitored fine. Looks like for FS7300 there is another SI plugin or some software.
Best.