Information regarding language visa and ausbildung

Your uncle can certainly help you find a good language school in Munich, can't he?
And regading conversion of language visa to apprentive visa, you should contact the Auslaenderamt in Munich to get a definitive reply. I assume it should be possible to convert

Thank you for the reply.
Yes!! My uncle can definitely help me but I was just looking for "more people, more experiences" .I thought maybe there can be more suggestions.
And about contacting to auslanderamt of Munich , can I just look for their mail account and email them or is there any other formal way of contacting?

It depends on the Ausländeramt: Some respond well (and some only) by email, others are best approached by phone, yet others require letters by post. In any case, they are not very service-oriented, and slow. If you write or call, do it in German - don‘t expect to be entertained in any other language (incl. English).
Your uncle probably knows the specifics of how to deal with Munich‘s Ausländeramt.