How to change from Residence Permit to Blue Card in Germany

Unfortunately, there is no ONE answer for this.
Fortunately, it is easy getting an answer.

It is completely based

• on your City
• on your case
• your Officer. 

You can have two same cities, two same scenarios but two different outcomes.

1. What visa do you have? It is a normal work permit §18 or §19b with ICT 
2. Go to the Ausländerbehörde, stop looking for answers in the 10th page of Google, you WILL not get it there. Note: You will probably need an appointment to visit the Ausländerbehörde but you can try your luck by going in at 7.45 AM (they open at 8 usually) and walking in and getting a Waiting Ticket. 
3. Explain to your officer that you have a visa and would like to switch to a different employer (preferably in German) 
4. Note down what the officer tells you. 

• Most probable: get the contract send it as an email to us along with Insurance Confirmation, Rental Contract and we will take a look. If all is OK, you can apply for a New Blue Card directly given your salary is above the limits. 
• Less Likely but possible: since you are on a ICT or short term residence permit, you cannot switch to a new employer directly from Germany. Need to go back to India and apply. 

      5. Done.   

Pro Tip: Always go to the Ausländerbehörde when in doubt. They are very friendly people most of the times. Speak broken German and they will be more than happy to help you.