How best practice with if statement loop?

I have code:

if(conditional)
{
   var r1 = dosomething();
   //do more here

   if(r1 > something)
   {
      var r2 = dosomething();
      //do something
      if(r2 > something)
      {
         ....
         //n if
      }
   }
}

I need help for this code is better. Can you show for me some suggestion? Thanks all!