https://www.einreiseanmeldung.de/

If you are entering Germany from another country and have visited a risk area or high-incidence area in the 10 days before your arrival, then you are in general required to stay in quarantine for 10 days after entry. If you have spent time in an area of variants of concern, then your quarantine period lasts 14 days.
Please check the quarantine regulations for your federal state (Land) to see which regulations apply to you.

Update: Air India didn’t issue the boarding pass until we have filled the form.

Registration link:

https://www.einreiseanmeldung.de/#/

Further information on the current entry regulations for Germany in connection with the COVID-19 pandemic and on the current exemptions from the quarantine obligation is available on the website of the respective federal state. Answers to frequently asked questions concerning the new digital registration on entry procedure can be found on the Federal Ministry of Health’s website.

Please check whether you have visited any of the following risk areas during the last 10 days and select those you have visited.