If you havent talked to the professor already, better to ask him how you should proceed.
Alternatively go to this link where it says you need a ' internship visa' . I am pasting the relevant paragraph..Hope it helps and all the best.
http://www.mumbai.diplo.de/Vertretung/mumb...ning__visa.htmlTraining (Internship) Visa
All Indian nationals, who wish to travel to Germany for training purposes, require a visa prior to their departure.
Please note that this Consulate General can only accept visa applications of those residing in Maharashtra, Gujarat, Goa, Madhya Pradesh, Chhattisgarh, Daman and Diu.
Visa applications will be accepted from Monday to Thursday between 1 pm and 2.30 pm.
Applicants will have to apply in person.
The visa procedure of this Consulate may take 6 to 12 weeks. Since all applications have to be referred to local German authorities, the Consulate has no influence on the actual processing time. Applications should therefore be filed at least 3 months prior to the intended departure for Germany. Simultaneous applications for short term visas and long term visas cannot be entertained.
Important:
Short term visas for tourist or visiting purposes cannot be converted into residence permits after arrival in Germany.
The visa fee amounts to the Rupee equivalent of 30,- Euro (subject to exchange rate).
Please note:
-Applicants are requested to prepare two complete sets of application forms before they proceed to the counter.
-Each set should contain the application form itself as well as photocopies of all documents the applicant wishes to submit.
-Original documents will have to be shown on demand only and will be returned immediately.
The following documents have to be submitted:
-A passport with minimum validity of 12 months;
-Two duly filled and signed application forms for long-term visa (for downloaded of form see below)
-Declaration of Genuineness of documents submitted (for download of form see below)
-Two identical photos need to be submitted out of which one is to be pasted on the application form, the second photo should be submitted loose.
Photos have to meet the following requirements:
Only photos of a very high quality can be accepted
Photos should not have any stapler pin marks disfiguring the face or the background
Size of the photo 35 mm X 45 mm
Proportion of the head in the photo must be 70 - 80 % of the complete photo
Photos should have a light background
-deputation letter from local employer
-details on internship from German (inviting) company
-health insurance coverage
Additional documents may be required in certain cases.
Sridhar