you can do AMIE from the institutions of engineers which is recognised as equivalent to BE. There are two sections . A & B Being a dip holder you are exempted from studentship ,andcan directly prepare for sec A .
SEE THE INSTITUTION OF ENGINEERS WEB SITE AND JOIN ANY TIME.
you can clear this in parts may be within 2-3 years depending on your capability.
AMIE is recognised for armed forces,and all other employment on par with BE.