Which Tibeto-Burman language groups have especially complex tone systems?

Within the Tibeto-Burman language family, the most elaborate tone systems are found in the Sinospheric Northern and Central Loloish groups, where systems consisting of six to eight tones are typically the norm.1

Additionally, the Baic, Karenic, and Jingpo-Nung groups are characterized as being highly tonal. In contrast, other groups such as Qiangic, Himalayish, and Kamarupan exhibit more varied systems, often containing both tonal and nontonal languages. When these latter groups do possess tonal systems, they tend to be more rudimentary, frequently featuring only two or three tonal contrasts.1