Dear Parthi dharan,
Welcome back to the Wefugees Community and thank you for reaching out to again.
I’m not an expert on the EU-law/freedom of movement but according to this official website of the Berlin authorities (exemplary), no language skills need to be presented when applying for the permanent settlement. Please follow the link for a full list of the requirements.
I hope this helps and please don’t hesitate to get back to us with any further questions.
All the best,