Can we save variables in SavedVariables in json format(type) ?
 

Can we save variables in SavedVariables in json format(type) ?

No. We are not allowed to save in other file formats, specify folders or directories, or specify other file names. For example we can't save in CSV either as a coma delimited file. However, you can save a string and then use regular expressions on it and you might be able to come up with something similar.

While you didn't ask but just to cover all the bases. You also cannot load files in other formats, load files from other directories, or load files from specific file names.

No, as Sharlikran alread explained the SV files are saved and read with lua format, at timings that the game defined (login, logout, reloadUI, zone change with laoding screens).
Read the WIKI about SavedVariables, it's all explained there.

We are not able to change the saved data format from lua tables to something else.
But you can use external tools to read/parese that SV files and transfer them to other files and websites how ever you want that to happen, as long as you know there won't be any "live data from the game".