@suman555,
Your college friends
don't make you who you are. I have no idea where you heard that. It's not true.
Lots of things make us who we are. Friends of any time frame are only a part of that.
That having been said, I will tell you what I just told someone else here - dating someone at work is generally a poor idea. If the relationship ends, it can poison your working environment.
But there's nothing wrong with being friends or even good, close friends - and dating once one of you moves onto another company.
So be friends. And do what friends do, which is everything from going to lunch together to making sure she gets home safe at night.
Don't blurt out feelings. Don't propose ... anything.
Just be friends. Get a feel for who she is as a person. You may find you're still interested. You may find she's not worth the bother.
Oh, and one more thing. I realize this is probably India and the culture is different, but it really bugs me when the concept behind caring for someone is so tightly wrapped up with something like, "i can take care of her".
She's an adult and she's got a job. She doesn't need care like an infant does. If you are going to ever ask her out, then you are going to need to respect her independence.