What are some good hobbies to pursue in Bangalore?

Knitting.

If you are stuck in the backseat of a cab / bus like a lot of folks were today, you'd finish a sweater by the time you reach your destination.

Also , very soothing on the nerves. And the needles make for great self defence if mugged.

Counting cars

Bansuri flute. There is decent penetration of hindustani music in Karnataka. You can easily find good tutors.

There are a lot of art and dance workshops as well weekly And learning an instrument can also be a fun hobby

Either have meditation so that you can have patience which stuck in traffic for hours or get pro level driving skills to navigate through traffic.

Join fitso for badminton

From where did you learn swimming? I am looking to learn as well.