From what I have read online, NVQ qualifications are used in the UK to assess certain skill levels.
Firstly, if you are a British citizen, you can enter Germany without a visa and stay for up to three months in order to **** for work. If you find a job in that time, you can apply for a work permit at your local immigration office (Ausländerbehörde). British citizens can do any kind of work in Germany, i.e. if doesn’t have to be any particular type of qualified position.
For most other non-EU nationalities in Germany, a work permit can only be issued for qualified work, i.e. jobs requiring vocational training or a university degree. As a NVQ level 6 is equivalent to a university degree, a permit on this basis would not be possible for you. If, however, your NVQ level 4 can be shown to be equivalent to a German vocation qualification, then you can get a permit to work in the area you are trained in. You need to apply for a visa from the German embassy in Lithuania:
I advise you to inform yourself here about the process of whether it is necessary to have your qualification recognised and if so, how to go about the process: