If your IELTS score in Paris is 5.5 and you plan to apply for a master's degree, you can consider going to a preparatory institution for studying abroad to study in the preparatory course. The preparatory course aims to help students improve their language level and make them adapt to and understand the international academic environment. Many institutions in Paris offer preparatory courses for studying abroad, such as Cours de Citizenship Fran of the world-famous Sorbonne University in Paris. Aise de la Sorbonne (French Civilization Course at Sorbonne University in Paris), Nanterre University in Paris, etc.

When choosing a preparatory organization, you can refer to the following aspects:

1. School reputation and qualification: Understand the reputation and qualification of the preparatory institution, especially whether it recognizes the cooperative relationship with the university/school where you apply for a master's degree.

2. Teaching quality: Understand the faculty and teaching resources of preparatory institutions, such as whether there are experienced teachers and courses that meet the needs of students.

3. Learning atmosphere and humanistic environment: consider whether the cultural and living environment where the preparatory institution is located is suitable for your growth and study.

When choosing a preparatory institution, it is recommended that you refer to the university application guide, website and the advice of overseas study consulting institutions to obtain more detailed and accurate information. At the same time, you can also make a self-assessment to decide whether you have enough time and resources to improve your language level, or consider other ways to improve your language ability.