Is it possible to relocate Rotax 912 oil filter?

Of course. There are automotive relocation/remote oil filter kits, that you can get through The Net or through your local automotive parts supply store.

 You might want to consider the

additional complexity (number of hose connections) and its impact on safety.

potential to negatively impact on oil circulation.

Remote locating the Oil Filter is a BAD idea.
Are you complaining that you cannot get a wrench on the Filter,  or you cannot get the filter OFF once it is loose?
If it is a wrenching problem, you need a different wrench.
If it is a clearance problem, we will need to see a photo of your exhaust.
Loosening all four exhaust pipes and moving the muffler slightly, often solves any issues.

Roger can you clarify why it’s a bad idea?

Roger might reply in a while, but I am sure he will agree.

Relocating the Oil filter will be adding at least a half dozen locations where something could fail or leak.
Oil failure is equivalent to running out of Fuel only worse.
The engine definitely will be seized and trashed.
This isn't a car or a boat where randomly stopping is an inconvenience and does not include a genuine risk of injury or death.
Consider these two offers; in both cases, you will be following GPS directions toward a destination of MY choosing that is at least an hour away. (Not traveling in a circle.)

I will offer you $100 to set a random 20-40 minute timer in your car, and when the timer goes off, you will turn off the ignition and pull over immediately no matter where you might be. 
OR ...
I will offer you $500 to set a random 20-40 minute timer in your aircraft, and when the timer goes off, you will turn off the ignition and land immediately no matter where you might be.

Which offer would you choose?

Beyond the increased risk, the Oil filter is admittedly a bit of a pain to access, but there is really no reason that the exhaust pipe should need to be moved to change it.

Airwolf Filter Corporation used to offer a relocation kit for the Rotax 912 as part number 13601. They must have also decided it was a bad idea because they stopped making it at least 10 years ago.  They still make the kit for Lyc and Conti engines as well as several others. Interesting that they dropped only the Rotax 912 version - I would bet Rotax had something to say about it.  I agree that it adds a lot of failure points, even if an oil change took and extra hour to R&R the exhaust I would still not remote the filter. 

Airwolf :: Remote Mount Oil Filter Kits