Dear Rajesh,
Simple plain answer to your querry is that your friend can avail leave encashment to the extent permitted by the company Corp HR policy only .However ,while going through your statement /question ,I have observed your question has not given light to the following key areas :
1) Is your friend working in a factory coming under factories act ? or a commecial establishment covered under the S&CE act of the respective state ?
2) In case ,he/she is working in a commercial establishment and is working in a branch situated in a state where there are more favourable or unfavourable terms inbuilt in the S&CE Act of the stae concerned and assuming that there are no certifed standing orders in the company approved by the appropriate govt ,approach to the problem in hand may vary .
3) Taking the querry to legal perfection ,it also requires light on dual wording you have used - " Accumulated/Carried forward " ? for ex : one can accumulate upto sixty from one point of view and in another ,one may take it as carry forward is permitted upto sixty days only .We ,HR professionals cannot use words like this assuming lay man's usage .Given to me ,I would interpret it as after crossing 3 or 4 years ,individual shall be permitted to carry forward sixty days only and not 90 or 120 as is the total entitlement
4) Finally ,why has he accumulated so many days ? is it because of exigencies of service ,and the management did not approve the leave beyond certain days ?