I'm assuming that this is grafted onto a standard, in which case you need to trim off the shoots below the graft growing on the main 'standard' stem.

It's a Hybrid Tea so prune February/March, just as new growth is beginning (when I had roses I used Mothers' Day as my pruning day).
- Cut out dead, diseased, rubbing and crossing stems.
- Cut back the strongest remaining shoots to four to six buds (maybe 6-8 in) from the graft.

It's quite a short bush really so you will only get something like a ball at the top of the standard, you won't get a waterfall/weeping effect. The pot is probably at the limit of small for a rose so it will benefit from feeding and mulching and will need watering regularly - it should also be lifted up onto pot feet to aid drainage and to ensure that it isn't standing in water after heavy rain.

Even with magnification, its hard to tell whether this was originally a standard rose or not - from what I can see, it looks not to be a standard because I can see 3 stems coming up from the top of the pot. If it was an ordinary bush when you put it in the pot, have you ever pruned it before? How long has it been in the same pot, and does the rose get full sun, or a lot of sun in that position?

There is a standard version of this rose on sale, and an ordinary, bush version - knowing which this one's supposed to be is critical, because the pruning instructions will be quite different.