Recently accepted for an unpaid research position – J1 visa question (India appointments / risk?)

I was recently accepted for an unpaid research position in the US with a start date of May 15 and have received my DS-2019.

Currently finishing an observership in the US on a B1/B2 visa (been here ~6 months) and will be leaving before my I-94 expiry to attend the visa interview in India around April.

For those who recently applied from India:

• What are the current J-1 visa appointment wait times?

• What questions are usually asked in the interview?

• Any risk of rejection given that I’m a postgraduate doctor but not currently employed in India?

Would appreciate any recent experiences. Thanks!