The Brainliest Answer!
From UK:-
     1)  Nominal Head - President
      2) Cabinet System of Ministers
      3) Post of Pm
       4) Parliamentary Type of GOVT
       5) Speaker in Lok Sabha
       6) Lower House more powerful
        7) Bicameral Parliament

From US
         1) Written Constitution
         2) The armed Force
         3) Fundamental Rights
         4) Provision of States
         5) Independence of Judiciary and  judicial review
          6) Preamble

         1) Fundamental Duties
         2) Five Year Plan

From Japan
         1) Law on which the Supreme Court function

From Ireland.
         1) Method of election of President
         2) Nomination of Member in Rajya Sabha by the President

2 5 2
It is said to be borrowed costitution .it was done by a group of 14 leaders under the able guidence of br ambedkar.the best rules and regulation ,rights and duties,and many good ideas were choosen to lead india in a very good path.and now it is known asthe best constitution. 
mark it as the best plsssssssssss
1 5 1