This question is about a man I know, who is the son of a Kashmiri Pandit mother and a Haryanvi Jatt father and he himself married a Kashmiri brahmin woman
What kind of marriage is this and what happens to the progenies?
Manu 10.10. Children of a Brahmana by (women of) the three (lower) castes, of a Kshatriya by (wives of) the two (lower) castes, and of a Vaisya by (a wife of) the one caste (below him) are all six called base-born (apasada).
10.11. From a Kshatriya by the daughter of a Brahmana is born (a son called) according to his caste (gati) a Suta; from a Vaisya by females of the royal and the Brahmana (castes) spring a Magadha and a Vaideha.
As said in a comment under the question, it falls under proscribed forms of marriages.
10.26. The Suta, the Vaidehaka, the Kandala, that lowest of mortals, the Magadha, he of the Kshattri caste (gati), and the Ayogava,
10.27. These six (Pratilomas) beget similar races (varna) on women of their own (caste), they (also) produce (the like) with females of their mother’s caste (gati), and with females (of) higher ones.
So, Suta is considered a Pratiloma.
Quoting more about Pratiloma and Anuloma marriages from Agni Purana.
An anuloma marriage is a marriage where the husband is from a higher class than the wife. The offspring of such a marriage belong to the mother’s class. A pratiloma marriage is a marriage where the wife is from a higher class than the husband. Chandalas were born this way from brahmana women, Sutas from kshatriya women, Devalas from vaishya women, Pukkashas from kshatriya women and Magadhas from vaishya women. Chandalas are executioners, Sutas charioteers, Devalas guards, Pukkashas hunters and Magadhas bards. Chandalas should live outside the villages and should not touch those belonging to any other class.
Thus, it is clear, that scriptures condemn Pratiloma marriages, where the Varna of the wife is higher than that of the husband. The reason is that the children born out of such marriages add to the "confusion of castes" and they don't belong to the four Varna system.