Hi Rajasekar,
If you want to work in Germany – and you're not from the EU (Belgium / Bulgaria / Croatia / Cyprus / Denmark / Germany / Finland.); EEA (Austria / Czech Republic / Estonia / Estonia / France / Greece / Hungary / Iceland / Republic of Ireland / Italy / Latvia / Liechtenstein / Lithuania / Luxembourg / Malta / The Netherlands / Norway / Poland / Portugal / Romania / Slovakia / Slovenia / Spain / Sweden / UK) or Switzerland (while Switzerland is not in the EEA, Swiss nationals have the same rights as EEA nationals.) you'll need a work permit, along with a residence permit which will be linked to your residence status in Germany. The right to work and to what extent you can work will be detailed on your residence permit.
If you're joining a relative who has permission to work in Germany, you will also be allowed to work. However, in most other cases, citizens from countries outside of the EU/EEA/Switzerland can only work in Germany if the position cannot be filled by a worker from the EU/EEA/Switzerland.
As Germany is keen to attract professionals into the country long-term, such as natural scientists (biologists, physicists and chemists), engineers, IT specialists, other senior personnel and academics, these people are granted preferential permits.
Types of German work visa:-
1)Permits for general employment
If you are coming to work in general employment (that is, a job that does not require you to be highly skilled or highly educated). You will need to have a vocational qualification and a firm offer of a job in Germany (and show both evidence of your qualification and an employment contract or letter of intent). The permit is usually granted for one year and is extendable as long as your situation remains the same. After five years, you can apply for a settlement permit or EU right of residence in order to stay in the country indefinitely.To apply for a residence permit, contact the German embassy or consulate in your home country/legal country of residence.
For more information:
Contact the German embassy or consulate in your home country, or the BAMF Information service:
Monday to Thursday: 9 am to 3 pm
Friday: 9 am to 2pm
T: +49 911 943 6390
E: info.buerger@bamf.bund.de
For PhD programmes, kindly refer the link below:-
https://www.shiksha.com/phd-programmes-article-4677-1Hope this helps. Click on the thumbs up or mark it as the best, if you found it useful.
Wish you luck!