Solution:Padmasambhava, also known as Guru Rinpoche, was a legendary Buddhist master who brought Vajrayana Buddhism to Tibet. He had no historical connection with Nalanda University. Santaraksita studied at Nalanda and later spread Buddhism in Tibet.
Silabhadra was the abbot of Nalanda and taught the Chinese monk Xuanzang. Dipankara, an ancient Buddhist figure, is sometimes linked to Nalanda traditions but mainly appears in legends.
Among these, only Padmasambhava had no direct association with Nalanda, making him the correct answer. The others either studied, taught, or led the university, establishing strong historical links with Nalanda.