The world No.113 shuttler, who is sponsored by McLarens Group, put together four straight wins before narrowly missing out on the title in a gripping three-game final.
Ranithma opened her campaign with a commanding 21–8, 21–11 victory over Natalia Slobodova.
She followed up with a hard-earned win in the round of 16, rallying from a game down to beat Cecilia Wang 21–23, 21–13, 21–19.
She stayed in control during the quarter-final, defeating England’s Freya Redfearn 24–22, 21–15 after holding firm in a tight first game.
Ranithma then booked her place in the final with another composed performance, overcoming Denmark’s Athene Lyduch Thornild 21–17, 21–15 in the semi-finals.
The final saw her face Austria’s Wei Xu in a closely contested battle. Ranithma lost the opening game 16–21 but responded strongly with a dominant 21–10 win to force a decider.
The third game went point for point before Xu edged ahead late to claim the title 21–19, leaving Ranithma as the women’s singles runner-up.