Some websites shows, that it's not required for obc-ncl candidates to have 75% in 12th boards to get a seat in josaa counselling but some say it's required. what's the correct information for obc- ncl category? (If yes, then is it also required for ALL the GFTIs and CSAB counselling too?)

Ans: HI
Not able to trace in JOSAA's Business Rules. Most probably NO.

Performance in Class XII (or equivalent) examination
(Applicable only for candidates seeking admission IITs)
The candidates should have appeared for the class XII (or equivalent)
examination for the first time in 2023 or 2024 or 2025 and must satisfy
at least one of the following two criteria:
1. Must have passed class XII (or equivalent) Board examination with a
minimum of five subjects and secured at least 75% aggregate marks.
The aggregate marks for SC, ST, and PwD candidates should be at
least 65%.
2. Must have passed class XII (or equivalent) Board examination with a
minimum of five subjects and be within the category-wise (category
as per the central list https://www.ncbc.nic.in,
https://socialjustice.gov.in, and https://ncst.nic.in) top 20 percentile of
successful candidates in their respective Class XII (or equivalent)
board examination.
The percentile calculation will be done for all the required subjects in a
single academic year only. Therefore, candidates appearing for
improvement in Board examinations can EITHER appear in one or more
subjects and secure 75% aggregate marks (65% for SC, ST and PwD) after
improvement, OR, appear for improvement in ALL subjects to be in top 20
percentile (see Section titled “Regarding the cut-off marks for the top 20
percentile”) of the corresponding academic year