What is that decommissioned plane near Nadirgul Airfield?
This is right, this model is a C-47A-85-DL Skytrain, a variant of the "Dak" DC-3 selected by the US Army Air Force in 1941 as its standard transport aircraft. 


Image from Le Bourget Air &amp; Space Museum

It has been early used by Allied forces to drop paratroopers and equipment or to tow gliders behind the coastline for the D-Day and operation Overlord. 


C47 from 439th Troop Carrier Group and Waco with their invasion stripes taking off from England for Utah Beach, June 1944 (source)

It had a long history and was everywhere until the end of the war and in the post-war conflicts, e.g. many of them participated to the Berlin Airlift:


C47s unloading at Templehof airport in Berlin, 1948. Source

Differences with the DC-3 include:


cargo door
hoist attachment
strengthened floor
shortened tail cone for glider-towing shackles
astrodome in the cabin roof.


You said the aircraft was standing at Nadargul airstrip. This information has been very useful to find the exact aircraft. It happens the aircraft did have a long story, throughout eras of war and peace, linking people of many countries:


A C-47A-85-DL airframe with c/n 20012, is manufactured in Long Beach, California, by Douglas (source) for the USAF (registration 43-15546).
In 1946, right after the war, it becomes the French government property (F-BAXK) operated for cargo flights under Air France colors.
Sold in 1950 to Portuguese government to be operated from Lisbon by Aéro Portuguesa (CS-ADB).
1953: Leaving Europe when sold to Lebanon, operated by Air Liban (OD-ABQ).
Finally moving further eastwards to India, bought by Kasturi and Sons (VT-DTS) to deliver The Indu newspaper in distant areas until it is decommissioned and transferred to Nadargul where it is used now by the Flytech Aviation Academy for ground training (source).  


(Source)

A movie star

This aircraft is seen in the 1965 Hindi feature film, Gumnaam (video):



Stamps in Israel

The aircraft was used for the first aerial mail sacks sent in 1948 from Israel to European countries, when it belonged to Air France. Two stamps commemorated in 2008 "60 Years of Friendship between Israel and France":

  


  On June 9, 1948 an Air France DC3 airplane, registration number
  F-BAXK, landed Haifa, flown by pilot Georges Bernard and two crew
  members: communication technician Mr. Sortais and mechanic Mr. Boutet.
  The plane made an interim stop in Bucharest while en route to Israel,
  thus arriving with mail from both France and Romania. The plane
  subsequently left Haifa on June 11 at 6:36 a.m., bearing mail to
  France and other countries with which Israel had re-established postal
  ties: Bulgaria, Holland, Hungary, Yugoslavia, Poland and Switzerland.
  It also carried a mail sack bound for New York. After interim stop in
  Cyprus, Greece Italy and Nice in southern France, the airplane took of
  the next day towards its final destination, Le Bourget airport in
  Paris, where it landed on June 12, 1948 at 11:01 a.m. and delivered its
  mail sacks.


(Source)