I am trying to find out sports which are good for people of all ages. So that my aunt, uncle and other elderly I can play with in the garden. I thought about cricket and the soccer. And found those can be played but it is kind of hard. Apart from that I think age wise some sports can not be played. 

So what are some good sports one can play with people of all ages?

We have a huge kickball league around me that everyone seems to love!  And it is pretty much good for anyone to jump in on!

Well, the main ones at the Olympics are Shooting and Equestrian. But I'm not sure how helpful that is: they both require a lot of space, and the latter requires you to be rich enough to own a horse!

Baseball/Softball is always a solid choice as it can be played at a more casual pace for older groups.  I always found basketball to a great choice for this as it can be super intense or very laid back and is still super enjoyable.  Plus basketball can be a simple 2 person created event or a full team vs team sport without  much loss in the fun.

It depends on how active you all want to be. Bean Bag Toss is a good game that doesn't require too much energy but is quite fun.