Here it the account of Lt Gen Jacob from The longest 30 minutes
On December 16, General Jacob flew from Calcutta. Touching down on Dhaka, he went directly to the Headquarters of Pakistani Eastern Command and showed Niazi the written instrument of surrender which he had drafted all by himself and waited for the final approval that eventually did not come.
All the generals including Rao Farman Ali protested. They said it was a ceasefire arrangement they could sit for, not a surrender, let alone in a public ceremony and to the Joint Forces.
In his memoir "Surrender at Dacca" Gen Jacob has an elaborate description of the tough negotiation:"I was a little annoyed and pulled Niazi aside. 'I have been talking to you for three days,' I told him. 'I have offered you terms that you will be treated with respect and under Geneva Convention. We will protect all ethnic minorities and everyone. If you surrender, we can protect you. If you do not surrender, I wash my hands off anything that happens.'"
Then Gen Jacob conveyed the 30 minutes ultimatum to decide on a surrender or face the consequences and he then left the room.
Gen Jacob wrote:"Once outside, doubts assailed me. 'What have I done?' I thought. 'I have nothing in my hand. He has 26,400 troops in Dhaka and we only have 3,000, and that too thirty miles away.'"
For quite some time, Gen Jacob paced the veranda of the military headquarters in a city behind enemy lines. He was alone and unarmed.
He wrote:"The other officers present with him had in no uncertain terms voiced their extreme displeasure at my demand, but I remained unfazed. Logic was my sword, faith the shield. The fate of millions hinged on the reply of the enemy commander to my no-nonsense threat. Only I knew I had been bluffing. For me, this was a defining moment of my life. I used all my control to appear calm as I paced back and forth. I was completely alone. I wondered what would happen if he said no."