Is polytechnic equivalent to 10+2..

I have completed polytechnic DCCP course 10+3 years pattern from Andhra Pradesh...Recently i got selected as LDC in central govt department for which qualification was 10+2 or intermediate.. when I went for certificate verification the concerned authority checked my documents and said everything is ok...The next day provisionally selected list was placed in their
website and my name is also mentioned in that list...Now I received a letter asking for Equivalent certificate...I have GO issued by govt of AP stating that DCCP course is equivalent to intermediate.. WHAT SHOULD I DO NOW...PLZ HELP ME

Just enclose the GO issued by AP and ask them to treat your qualification of DCCP as equivalent to intermediate.  Provide attested copies of DCCP, GO with a covering letter and send it by regd. post..  (May be some institutions may not have such knowledge on GO, or that GO might have been applicable to certain courses alone)