The New Kadampa Tradition (NKT) gets along well with most other Buddhist groups, such as Theravadin Buddhists, the Triratna Buddhist Community (FWBO), and so on. However, NKT Centers and practitioners have run into problems with certain Tibetan Buddhist groups — those who were influenced by the views and politics of the Dalai Lama at the time that he was banning the practice of the Wisdom Buddha Dorje Shugden, and Shugden practitioners were being subsequently harassed and persecuted.
For years after the Dalai Lama issued that ban, and NKT practitioners protested against this, NKT students and Centers experienced numerous incidents of criticism and discrimination in the real world and on the Internet. They were accused of being evil spirit-worshippers and cultists, even murderers and Nazis. They were heckled, shouted and spat at on the street, denied entry into other Tibetan Buddhist organizations, warned against attending or returning to NKT Centers, threatened face-to-face and over the phone. They had branch classes cancelled, Centers vandalized, publicity torn down or defaced. They were barred entry to online Buddhist forums such as E-Sangha and Reddit. Things are better now, but there is still harassment online; and Reddit, for example, still won’t allow any Kadampa Buddhist to post or comment on the R/Buddhism page.
Despite all of this, what has been experienced by NKT practitioners pales next to the persecution suffered by Dorje Shugden practitioners in India, some of which is documented here: Wisdom Buddha Dorje Shugden ~ Why is the Dalai Lama Suppressing Religious Freedom?
Not all Tibetan Buddhist groups are opposed to the NKT, by any means. There are many Tibetan Buddhists relying upon Je Tsongkhapa’s and Trijang Rinpoche’s lineage teachings and Dharma Protector Dorje Shugden in India, Tibet, and the West who greatly appreciate the NKT and NKT practitioners. This is not least because Ven. Geshe Kelsang stood up for them and is considered both a great hero and a fully realized Buddhist master.
Several monasteries were able to open in India due to the support of the International Shugden Community (ISC), with hundreds of monks (many of whom had ben expelled from their previous monastery by the Dalai Lama), including Serpom Monastery (pictured) and Segyu Gaden Phodrang Monastery.
There are also various Tibetan Buddhist groups who have their own problems with the Dalai Lama, such as those Kagyus who oppose his choice of the head of their tradition; and therefore they never jumped on the bandwagon of condemning the NKT for continuing to rely on Dorje Shugden and speaking up for Dorje Shugden practitioners in defiance of the Dalai Lama’s ban.