Rice, Aryans, Dravidians, and Mundas

"warizi" is not the most common form of the word for 'rice' in Afghan languages.
The word is given as "vrize" or "wrize" in other etymological dictionaries.

Old Persian "brizi" (Pahlavi : brinj) does seem to come from sanskrit "vrihi".
The z/h correspondance between iranian and aryan is well known.

Carl D. Buck in his (old) "Dictionary of synonyms in IE languages" writes :
"Rice is of oriental origin, and likewise without doubt greek oryza, which is the
source of all the European words. This is _probably a distorted form_ (though
Iranian) of the word seen in Sanskrit vrihi, Afghan wrizhe, etc."

But the greek/latin form Oryza still seems to be closer to the Dravidian words.
Ex. Tamil : "arici" (rice without the husk) or "ari" (rice)

I tend to be in agreement with Michael Witzel's views on the spread of Indo-Aryan in the subcontinent.
In "substrate languages in Old Indo-Aryan (Rgvedic, Middle and Late
Vedic", he argues that a Munda or another austroasiatic language was spoken in Pandjab and Sindh
before the arrival of first Dravidians and then Indo-Aryan speakers.
The Dravidians would have emigrated to the Iranian Plateau before arriving in India. Pasturalists,
they first came to Baluchistan, then Sindh, Gujarat, before finally spreading southwards into India.
This would account for the presence of Dravidian speakers in Baluchistan (Brahui) and a trail of
Dravidian placenames ending in 'wali' (from Dravidian pali, 'village') expanding southwards from Sindh,
Gujarat and into Central India. The Elamo-Dravidian theory linking Dravidian to the language of Elam
in present-day Iran is somewhat more controversial. This Dravidian expansion would have started
circa 3500 BC.

"It is indeed possible that the Dravida constituted a first wave of central Asian tribes that came
to Iran before the IA, just as the Kassites came to Mesopotamia before the Mitanni-IA. In that
case they knew the horse already in Central Asia, but would not have taken it over directly from
the Indo-Iranians (as may be indicated by Brahui (h)ulli, Old Tamil ivuli ‘horse’, etc., different from
Indo-Iranian. açva ). In other respects as well, they have not been influenced by the Indo-Iranians."(Witzel)

Witzel finds up to 300 para-Munda loanwords in the early Rg Veda (1700-1500BC), but no Dravidian words.
Dravidian words (such as phala 'fruit' for instance), he argues, only start appearing in middle and late
Rg Veda (1500-1200BC)
This might mean that the first people the IA encountered in the Punjab (and perhaps the people
of the Northern Indus Valley Civilisation) were Munda or Para-Munda speakers. The Dravidian influence
from Sindh and Gujarat came later.
In Witzel's model, during the second millenium BC, numerous pockets of different language families
were scattered throughout Northern India, Pakistan and Afghanistan, with para-Munda (in Eastern and Western India),
proto-Dravidian (in southern Pakistan, Sindh, Gujarat and spreading into Central India),
proto-Burushaski in the Hindu Kush, and, gradually infiltrating from Afghanistan and into Pandjab, Indo-Aryans.

As for the word rice, Witzel believes that there are two parallel forms involved :
a southern "Sindh" variety" (which the Proto-Dravidians picked up from the southern form
of Harrapean - Para-Munda - used in Sindh) and a northern "Pandjabi" variety (which the Indo-Aryans
picked up from the northern dialect of Harrapean - Para-Munda - used in Panjab).

"The word for 'rice' occurs in a Sindh and a Panjab variety. The Sindh version, closer to Dravidian,
has been transmitted further west, along the southern trading route to Persia and has entered western
languages from there (Greek oryza).
Whether rice was otherwise known to the Rg veda is doubtful. [...]The Dravidians were originaly no agriculturists
themselves [...]
It is through the mediation of the Dravida in Sindh, Drav. *varinci ‘rice’ must have reached Iran
(> M.Pers. brinj ), that is not,as otherwise common, via the northwestern Khaiber Pass, as in this
region another form of the word is found, with *vrijhi > Pashto wrizi, etc.
This may mean, on the one hand, that the Dravida themselves were immigrating at the time of
the older Rg Veda, or that they only influenced the Panjab in the later, Middle Rgvedic period, coming
from Sindh."(Witzel)

The Sanskrit "vrihi" and Dravidian "(v)arici" could conceivably be independant borrowings from
a Proto-Munda *@rig (ultimetaly of Austronesian origin).

The "Northern dialect" of the Harrapean language would have been *vriji > (Skt) vrihi

vrihi < Northern Indus(?) *vrijhi < ProtoMunda *@rig < Tib./Malay (')bras < S.E. Austric (??) **@b@...

While the Southern dialect of the Harrapean language would have been *vari(n)ci > (Tamil) arici

The Southern dialect would therefore show the typicaly Munda infix -n- in some of its forms (those that gave
M. Pers. brinj and moder persian birinj, as well as some central Dravidian languages like Gondi wanji) but
not in others (Tamil arici, etc.)

All this is highly speculative, many of the categories used are hypothetical, and a simpler derivation of
'vrihi" directly from a Proto-Dravidian form *(v)arici cannot be ruled out a priori.

As for Tibetan 'bras and Burushaski bras, well that seems even more conjectural to me.