Well, it depends on what you have. The 10/22 comes with a proprietary rail, and is tapped already for a scope. If you have one which isn't, you need to decide what sort of mount you want. You might want to add a Weaver or Picatinny rail, or you might want to mount the scope bases directly into the receiver. Once you've made up your mind, then you get it tapped for a scope.. I'd recommend you leave this to a qualified gunsmith.
Follow the instructions provided with the scope/mount. You need to make sure you have a scope with rings that will fit on a "Dovetail" scope base rail. They have 3 main bases; dovetail- mostly for air and pellet guns...some 22's also, Weaver style, and Piccatini rail systems.
You could either take it to a gunsmith or put it on yourself. I had a Ruger 10/22 and I think it had a scope rail for mounting. Should be just a matter of tightening it onto the rail and sighting it in.
You will need a gunsmith to drill and tap the reciever to install a scope mount. Early 22 rifles did not have the dovetail grooves.
It is possible
Best left to a gunsmith
Contact Ruger
Im looking for one myself. You might have to get it tapped by a gunsmith or a scope rail. I havent seen any custom mounts for it.
$25-$50, depending on condition.
50's or so
No, the scope is for airguns and .22 rimfire...not airsoft Yes, You can get a 12mm to 20mm adapter.
One can be made
You have a Grade I Browning takedown semiauto .22 rifle made in Japan in 1986. Browning offers a scope mount for that rifle, their item #12333. Aftermarket mounts are available from Leupold, Burris, etc.