It should have leaves on as they are evergreens... if not snip a piece of stem to check it is green inside - if it is brown it may have died!
They can be a little tender and like a bit of shelter from cold winds, they also enjoy the sun.
If it is alive, it can be kept in a pot but make sure it has enough root room to grow - if it is in a 2-3 litre plastic pot - perhaps get one about a foot across - add some good potting compost and water well. they can be pruned in a fan shape to grow against a wall - or given some support and left to ramble. Shorten back the stems each spring to keep the plant bushy with plenty of shoots low down as well as higher up. Then it should get covered in flowers. Good luck!

Passiflora can be killed back to the ground in a severe winter, but usually grows again - however, we haven't really had a severe winter, though all plants are more vulnerable to cold in pots. Some varieties of Passiflora aren't fully hardy - you don't say which one you have, but if it was P. caerulea, scrape back a little of the bark or outer covering on the stems - if they;re brown and dry inside, the stems are dead, but you might find new growth starts next month or even May.

I scraped a piece of stem and it is green inside, so fingers crossed! Thank you.