Which strategy in stock market works best for income generation ?

None of the above. Investing in stock is a business. That means it requires focused effort, lot of experience and good amount of luck. After 2020, we have seen only a one way market, with hardly any correction. So everyone is talking about investing in stocks. Most people have conveniently forgotten the bad phase between 2015-2020.

When people shell shovels, its best not to get into gold digging business.

Buying NIFTY ETF whenever NIFTY falls 1% some guy in reddit is doing this