Notice period before resignation

I joined in service as a Sub Registrar(Gr ‘D’ under WBCS & other Allied Service)in the year 1990. I got a promotion to the post of Additional District Sub Registrar in the month of October, 1996 & my scale was fixed in the then scale no.16. But i got benefit under C A Scheme with GP 6600 in PB-4A on completion of 8 years of service in October, 2008 counting from the year 2000 (as our service was uplifted as Gr A service since the year 2000) and, then promoted to the post of District Registrar in the same scale with same GP after allowing a benefit of pay fixation with an increment. Then in the year 2013 i got a promotion to the post of DIG Registration with GP 7600 in PB-4B with minimum initial band pay of Rs 28000. Shall i be able to get the benefit under C A Scheme with GP 8700 in PB-4B in the month of October, 2016 on completion 20 years of service in total counting from the year 1996 subject to availability of vacancy ?