not the previous replier..

but you may look at the link that guy replied..

but usually, Fresh Grad comes in as D/E if you are Tap.
Grade D,E,F = Associate Engineer
Grade G & H = Engineer
Grade I = Senior Engineer
Grade J = Lead/Executive Engineer

D-F can achieve within 2-5 years, as TAP comes in as E
G & H are the mainstays of GT, can achieve within 2-3 years from F
I & J is RO(Boss) grade can achieve witin 4 - 10 years

but YMMV