Do you need anything out of the ordinary due to covid?

depends on states man, many no issues, some have tests etc

1. Install aarogya setu on phone 2. Mask is madatory 3. [VERY IMPORTANT] Check the latest travel guidelines for both source & destination states here: https://www.goindigo.in/information/state-regulations.html. E.g. Mumbai had some rules for mandatory self-quarantine on arrival. You could get an exemption if trip length was less than a week, but you had to make an online application for it. All state-specific processes are in the linked website. 4. Fill health declaration (self-assessment). Depending on the airline, this is usually done while booking tickets or web-checkin for boarding passes. 5. Prior to boarding. the airline will provide you with face shields & masks. If you're in the middle seat, they may even give you a PPE coat.

indigo page is outdated, flew from andhra, no quarantine, no reg needed

For domestic - Just make sure to web check in, have a mask with you, carry boarding pass in phone or print. But it may depend from flight to flight and city to city. Best to read their instructions.

Can you travel without aarogyasetu?

Actually, just did GOA-BLR-RJM - was never once asked for aarogya setu at all in 4 flights 😛 But, yes you can be asked anywhere - keep the app, turn bluetooth off to avoid crap tracking

Carry a pen! You might be asked to fill a health declaration form, and you could find yourself searching for a pen. So yeah, with all the advices above, carry a pen!