Second income ideas?

Freelancing, it helps

You can go by your username. But it all dependa if you are a skilled mazdoor or not. If you are a skilled one, try to do teaching/technical training and/or freelance projects.
If you want aomething not inclined with tech, maybe setting up some fast food stall would work. Like maybe momos or soya chaap or biryani. Get a worked, spend like 20-25k for basic setup of cart and utensils and monitor the junior mazdoor. You can easily earn anywhere in the north of 3k per day depending on what you set up. A simple gol gappa stall can get upto 4k per day. A simple soya chaap corner can get like 8k per day etc.
If not the traditional cart ones, you can even get the kiosk set up. Some people also do the online reselling business. This is something to begin with, rest there are plent of things to do, like paper production and all but that needa investment to buy the whole machine which punches holes, binds spiral and makes a register/copy and you would also need to get a dealer to trade your product.
Let me know as well what conclusion you reach!