Assuming you are General Category Candidate, I believe you must target atleast 95 Percentile to have fair chances in securing a seat at MNIT Jaipur B.Arch, perhaps if you are from Other State Quota 96+ seems a much safer estimate. With nearly 60k aspirants appearing for B.Arch JEE Main Paper 2A, the Cutoff for MNIT Jaipur B.Arch for General OS last year was 2.5k, while for General HS was 3.5k.

For more information as well as Cutoffs of B.Arch in NITs do follow the link below

https://engineering.careers360.com/articles/jee-main-cutoff-for-b-arch-b-planning/amp