Stoke, managed by former Rangers boss Mark Hughes, had taken the lead in the first half through Mame Biram Diouf, only for Peter Crouch to stab a header from Steven Caulker into his own net just before the break.
Crouch, who played at QPR as a youngster, looked to have secured victory when he swept home from close range on 51 minutes.
But with two minutes left, Croatian Kranjcar, signed on loan from Dynamo Kiev, swept in a fine 20-yard free-kick having been upended by Stoke substitute Steve Sidwell.
Kranjcar, 30, helped QPR win promotion back to the Barclays Premier League last season before agreeing another loan spell for 2014-15.
"It was a great free-kick, they were bad challenges and he punished them," said Redknapp, who also had Kranjcar in his teams at both Portsmouth and Tottenham Hotspur.
"He came here and I think we pay a third of what he was earning in Russia, and they don't pay any of it, he took a massive cut in wages to come back here, that is how much he wanted to come back.
"It is very rare to see a boy do that.
"He had a massive, fantastic contract in Russia and wanted to come back here and play football."
Redknapp was delighted QPR fought their way back into the match, having looked vulnerable on the break when Stoke missed several chances to wrap up victory.
"It is a good point, make no mistake, when you are 2-1 down with five minutes to go and come back to get a point, that is vital," he said.
"We did not give up and keep going.
"If we can get everyone fit and keep picking up points, we will be okay."
QPR had made four changes from the team beaten 4-0 at Manchester United last weekend, Chile forward Eduardo Vargas coming in for his first Barclays Premier League start.
Redknapp, though, was forced into changes through injuries to both captain Joey Barton and Jordon Mutch, while fellow midfielder Sandro is out with a knee problem.
"Joey and Mutch have done hamstrings, Sandro did his knee yesterday, so it is a problem for us, we were a little bit mix and match
I could not even pick a team yesterday morning and I took a bit of a gamble with them," Redknapp said.
"They are all struggling a bit and it does leave us a bit short."
Stoke boss Hughes was disappointed the visitors could not see out the match, Steven Nzonzi sidefooting a great chance to make it 3-1 wide following another quick counter.
He said: "In terms of what we produced and chances in open play, we were clearly the better team on the day.
"We should have had enough about us to see the game out, QPR looked like a team beaten at that point.
"Unfortunately we just encouraged them a bit and gave away a free-kick in a key position and with the technique like Kranjcar has, then he may well have the ability to score.
"But it is another point on the road, which was a struggle for us last season, so there is a positive, although the feeling is we did not get what we deserved."
Former QPR boss Hughes was sacked following a testing 10-month spell in November 2012, after which the west London club slipped to relegation.
The Welshman was expecting a hostile reception, and it was only a few minutes before chants against him rang around Loftus Road.
Hughes, though, took it all in his stride
He said: "I expected a little bit of stick, and that is understandable.
"But credit to the Rangers fans, they made their feelings known and then got on with supporting their team, like they should do, so it was not a problem."
Source : PA
Source: PA