The company should have been open and clear about their requirements from probationers right from beginning.
Your probation period was for 6 months, when did they tell you about this costly training?
It looks like without signing bond they will not train you and probably look for alternatives.
What is the reluctance to sign the bond?
Legally, there is nothing much which can be done by you in practical terms.
2. I am planning to pursue higher studies and the bond is of 2 years. This will become a hindrance.
3. I can understand there is nothing much I can do in practical terms here. But I would really appreciate if you can kindly name the clauses/acts relevant to my case. I am not planning to defend myself against the company, I just want to gain some knowledge, that's all.
In my suggestion you consult any consultant deal in this field with your appointment letter if some way remain out.