Hi @sai_6847,
Thanks for reaching out, and I’m sorry to hear you're running into this issue. When you type out text in Illustrator, it's not automatically grouped, so if you're unable to ungroup it, it's possible that the text is still a live text object. Try selecting the text, then go to Type > Create Outlines first. This will convert your text into individual vector shapes. After that, you should be able to ungroup them using Object > Ungroup.
Also, just to confirm, are you working with regular text or did you already apply any effects? If it's still not working, please let me know which version of Illustrator and operating system you're using, and if possible, share a quick screen recording, so I can take a closer look.
Let me know how it goes!
Abhishek