Work / qualification required to join as a teacher in international schools [8]

hi all,
I m from India.I live in Warsaw.I am looking for a job to join as a teacher in some international school.I want to know what qualification should i have?I have my Bachelors of Science from a University in India.I am very very fluent in English.I have jst started learning polish.So i think International school is best for me,as there is no compulsion to speak polish.

So pls help to know abt the qualification and where should I join to get that course or certificate to be a qualified teacher.