As with many involvement challenges, the first step here is not a meeting or a new volunteer job but rather a welcoming event that helps parents of different cultures connect with your group. My favorite event on this front: International Night.
You can check out my recent video blog on International Night for some of the reasons why it's a great event.
It's a really flexible concept. You might collaborate with your geography or literature teachers to make the night academically focused. It's also a chance to create an amazing food-centered night with home cooking from many different places. Music and dance, too, can be a great fit. There's no right or wrong answer as long as you're creating a natural welcome mat for the parents you're looking to reach. And then working smartly after the fact to keep those connections going.
Here are two good articles in this area:
Good luck!