You're right, dasa sir - it's not clear if Shobana is dead or not.
She just vanished from the serial...it was not shown what happenend to her after the gun shot, or even if anyone took her to the hospital or even if a post-mortem report was given to the police. Ganga was nowhere near Shobana when she handed over the sim card to Nithila, just before her death. So I don't know how the police concluded that Ganga is responsible for the gun shot, unless it came from Shobana's mouth.
Maybe they plan to bring back Shobana's character later into the story, like you said.
But a few characters in the serial have declared her "dead" for now. And if she really died according to the story, that was a sad and pitiful way of killing her character. I mean, everyone around her left her wounded on the floor...and ran to the nearest computer to find out what was in the sim card (before her "death"). Maybe they were not aware that she was gun shot?
By the way, in Friday's episode...Jeeva brought a garland to congratulate Aadhi. I was very sleepy when I saw that episode, but after bluegal mentioned how Aadhi was bending her head to receive the garland...I remembered her funny facial expression at that moment. It really was a garland, just like bluegal said.