I am from Tunesia. Am I eligible to enter Master studies with my Licence?

Hi Nadim.
Here's what I found out:
If your Licence allows you to enter Master studies (or equivalent) in Tunisia, you're eligible to enter Master studies in Germany as well.
In this regard, the German Rector's Conference (HRK) states:

Holders of a foreign academic degree, who would like to study for a master’s degree (or equivalent) at a German university, may apply directly to the university of their choice. They need to provide evidence on the comparability of their education to a German bachelor’s degree. The qualification has to be an entrance qualification to postgraduate programmes (or an equivalent academic level) in the country of origin as well.

But also:

The responsible board of a university decides on the admission to postgraduate studies or doctorates on the basis of their respective regulations. If necessary, the university may ask the Central Office for Foreign Education (ZAB) for an evaluation of the foreign degree.

So you can just go ahead and apply for your desired Master's degree programme.
❗Be aware, however, that there might be additional requirements (such as German/English language skills and/or relevant professional experience) and that the application process as well as evaluation take time.
To give you an example, the M.Sc. Industrial Engineering and International Management campus study programme at Fresenius University of Applied Sciences has the following requirements:

The prerequisite for admission to this degree programme is a successfully completed Bachelor's degree (with a grade of 2.7 or better) in engineering, industrial engineering or a related subject in the STEM field with at least 180 ECTS credits, or a comparable academic degree, such as a diploma. In case of a deviating grade point average, the eligibility to study can be proven by a separate selection interview, if necessary.

And further:

In the previous Bachelor's degree programme, at least 60 ECTS should be attributable to STEM subjects (mathematics, information technology, natural sciences and technology), 10 ECTS to business or management and 10 ECTS to your Bachelor's thesis. [...]

Otherwise, since there are quite many vendors in the private study sector it's hard to give a universally valid answer on specific requirements.
💡Also: Feel free to contact the student advisory service of the respective university if you need more info.
If you haven't decided on a study programme yet, you might want to check out these programmes directed at international students to get some inspiration:

Hope this helps.
Kind regards