Bond transfer from Indian railways to PSU

Dear sir/ma'am, I am currently a trainee in railways but has been selected in other PSU for higher post job. I had a bond with railways to serve 5 years and amount is equivalent to stipend received during 1 year training. Now according to the rules the bond should be transferred to the PSU for remaining service period. But I am not sure how much will be the bond amount. Because in the railways my bond amount is around 5 lakh but the PSU has their own bond of 60 thousand rupees. Please refer below rules for reference. (i) Non-gazetted Railway employees who have received training at Railway expense whether in the form of an ' induction training ' or in a specific avocation may be exempted from refunding the cost of training in the event of their selection to other posts under the Central or State Govt. or in Public Sector undertaking / Autonomous Bodies wholly or substantially owned/financed /controlled by the Central Government or a State Govt. However, a fresh bond should be taken from such employees to ensure that they serve the new employer for the balance of the original bond period. The Railway Administration with whom the employee has executed the original bond, may at the time of forwarding of his application (and if it is not possible, before his release) for another post, may write to the department/organisation under whom the employee intends to take up another appointment, intimating them about the bond obligation of the individual and clarifying that in the event of his selection for the new post, his release will be subject to the condition that the new department/organisation obtains from him a fresh bond binding him to serve them for the balance of the original bond period and in case he fails to serve the new department/organisation, or leaves it before completion of the original bond period, for a job, where exemption from bond obligation is not available. The proportionate bond money should be realised from the individual and refunded to the Railway Administration, with whom he had originally executed a bond. What is the meaning of proportionate bond amount according to this?