Soundiiz is supporting the import of JioSaavn playlists to other streaming services with the Share link provided by JioSaavn.
For that, simply go to your playlist on JioSaavn and use "Share" button to get an URL using "Copy Link".
Then simply go back to Soundiiz, tab Playlists and use "Import playlist" button in top right of the interface and select "By URL". Then paste your URL and follow steps !