Thank you for sharing this detailed and practical guide @SharmaKK I also visited Delhi in 2024 and traveled onward to Punjab, Haryana, and Rajasthan by train and bus. Since my trip had a specific purpose, I couldn’t explore many attractions, so your budget sightseeing tips will be very helpful for my next visit.
Here are a few of my Delhi travel experiences: 
Hello India – New Delhi: The Delhi stories -New delhi[Palashinendlessdestinations] The Delhi Stories – Nizamuddin Auliya Dargah: The Delhi stories - Nizamuddin Auliya Dargah[Palashinendlessdestinations] The Delhi Stories – Hazrat Qutubuddin Bakhtiyar Kaki Dargah: The delhi stories - Hazrat Qutubuddin Bakhtiyar kaki Dargah[Palashinendlessdestinations]
Looking forward to trying the HOHO Bus or Double Decker Heritage Tour on my next Delhi trip. Thanks again for the valuable information!