My kid is always trying to play with the home-theater which is under the TV. How can I stop him and how to protect the equipment (is there any cover available to keep children away for touching the home-theater?)
There are two options. You could buy or make a cover, and this will work for a while, in your house. It will not however sort out the same problem when you visit other places, so a much better solution than child-proofing your house, is to house proof your child.
Be with them when playing. Guide them. Tell them no when they try to play with things they shouldn't.
Yes, it takes a bit of time, and it requires a bit of effort, but it helps build a good learning ethic and means you are interacting with your child, rather than just building a wall.
The huge benefit we found when doing this with our three was that we could take them anywhere, even places with delicate glass ornaments at toddler height, and we knew they would be safe.
Definitely worth that extra time investment up front!