Hello Dimitry,
important is, to get the telescope mount as close as possible to the balcony railing. A pier or narrow tripod or a combination could be interesting. Maybe a normal tripod could be rotated a bit so the mount is closer to the balcony railing to get as much field of view as possible.
I think something like the Skywatcher Explorer-130PS on the AZ EQ Avant mount would be a good possibility. Unfortunately I don't know the AZ EQ Avant on my own so I cannot tell my own experience with this mount.
Maybe this would also work on your balcony:
https://www.teleskop-express.d…man-equatorial-mount.html
Kind regards and clear skies,
Roland
