TDS - Technical service

Sec-195,115A and 9.
Rate as per Income tax act1961, is 10.4%. check for applicability of surcharge also in your case.
Ask for TIN or unique number available with person in germany to whom payment is to be made.
Rate as per DTAA with germany is 10%.
File form 15 CA and 15 CB.
15 CB is to filled by a chartered accountant.
Ask for no PE declaration from germany person.
Be aware if germany people have PE in india then 44DA shall be applicable.