Plz reply early How to calculate lease rent p.a

My company is planning to buy computers for Rs.60,00,000. I have been given the reponsibility to prepare a project report showing the lease rentals p.a. under the two options of leasing i.e. Operating lease and finance lease. The IRR given is 10% and R.V. is 15%. Please provide me support or guidance in calculating the lease rentals. I have to coplete this job by 29.1.2011 morning. so please help me.

Ajay