India completed a 76-run victory in the third and deciding match of the series in Paarl, boosted by an excellent 108 from Sanju Samson as he was one of the few to master the slow wicket.
Both sides rested key players with a two-test series starting on Tuesday. India in particular gave several inexperienced players a run.
"It was good to see what everyone did, they showed fight throughout the series," Rahul said.
"A few of them were nervous to start off, so I just let them be to get used to international cricket and the pressure.
"I am very happy for Sanju, he has been a great performer in the IPL (Indian Premier League) and unfortunately has not had enough chances near the top of the order for various reasons.
"There are so many world-class players in India that are settled at the top of the order."
Rahul, who featured in the World Cup final loss on home soil against Australia last month, said it is good to be able to play with a smile again.
"We had a disappointing result in the World Cup final and I had some time off. It was nice to get back on the cricket field and to be part of this group, putting up good performances.
"My message (to the players) is always to enjoy the game and each situation. Give your best and don’t worry so much about the result.
"It is a young group. They have played a lot of cricket but not at international level."
Seamer Arshdeep Singh was named player of the series after taking 10 wickets.
"The IPL has been a very good platform for us youngsters, there isn't a big gap between IPL and international cricket," Singh said.
"You understand the mindset of international cricketers and it helps. We are all loving the chances we've got. We'd love to give our all in the future and do well."
