Do i need to pay the hospital in case of planned Cashless Hospitalization?

I have applied for cashless hospitalization from the TPA. The authorization has been granted to the hospital to proceed further. But the hospital authorities demand that i pay an amount of Rs. 10,000 prior to hospitalization in advance. This is for the hospital expenses that would not be covered by the insurance. When i enquired the TPA, i was suggested to pay the advance. Please shed some light on this. Is it really necessary to pay the advance?