Will you please tell me Upto which level I have to study English for the post of TGT English???

TGT stands for Trained Graduate Teacher. For TGT one should have studied English in 12th and you should have to graduate or post graduate in English

To Apply for TGT you must have done graduation in English with a bachelor degree in education.(B.Ed).

Age criteria for TGT:
You must be above 21 years.
There is no upper age limit for this exam.

Syllabus for TGT Exam

Part -1
General Awareness
Current Affairs
General Science & Indian Constitution
Reasoning
Quantitative Aptitude
Teaching Aptitude etc

Part-2
English -20 questions
Hindi -20 questions

Part 3 covers your own subjects.