Industrial bond breaking procedure

Hello sir, I am a mechanical engineer. I am working in japanese MNC company as a temporary employee for more than 6 years. First 3years I was working as machine operater. And I moved to R&D department through internal interview. After entered into R&D department I got a chance to go to Japan for internship training through the company. The training period was one year. During that time my total expenses were spent by the company. Before I went to japan I was asked to sign the bond of 5years. And they said you will be promoted as permanent employee after returned to India. But that was a oral promise. I believe that and I signed a bond and I went to japan. After training period was completed I returned to India and joined a same company (at Jan-2019). It was one year completed since my return date from Japan. Still I am a temporary employee. The salary is too low. I couldn't get any benefits from company. Totaly 6years and 5months has completed as a temporary employee. They didn't even respond I asked for a confirmation order. Still 4 years remaining in the bond period. Now I got a offer from other company. And I decided to resign my job. And i want to break the bond. There is no specific amount is mentioned in my bond. It was mentioned that the "amount which was spent for training will be claimed from employee if they break the bond" like statement. I need some some suggestions 1. Is there any possibility to break the bond without paying the money (because still I am a temporary employee). 2. If I need to pay the money, how much will be asked by the company. However the amount spent for my training period in japan was too high. I can't pay that much money. Is there any criteria for fixing the amount. 3. If I abscond without giving any information, what will be the action can taken by the company. 4. If I challenge the bond in court, how much time will take to get judgement. 5. Is the bond legal to temporary employee also.