Which car brands to consider & avoid for a second hand car ?

Put VW in the exclusion list. Reliability of many is nothing special and you'll pay through the nose initially as "everyone" thinks VWs are great. The advantage of this is the car may hold it value well.

Nissan and Renault are very closely linked and the Grand Scenic is an excellent MPV. The 1.5 Dci in Renault/Nissan/Dacia is also one of the more reliable diesels out there.

Mitsubishi and Honda are around in small numbers.

For me it woukd be either Toyota, Renault/Nissan or Kia/Hyundai.

Buy the smallest car with the biggest engine. Stellantis isn't any worse than VW when it comes to reliability, the problem is small cc over stressed engines built for marginal economy gains over reliability.

Yes, I never had an issue getting parts for Toyota Estima's or Toyota Voxy's etc

Nothing wrong with PSA 1.6HDi 8v, bullet proof

Stay Away from mitsubishi outlander diesel. They can have big problems below year 2020. A good few of the Volswagon tiguain have oil consumption issues. Doesn't really matter the year. I have one. A mechanic told me it's luck of the draw now ehen u get a new car. One in ever 4 or 5 will have issues early.

OP you will will get better advice if you list a handful of make/models that you have actually looked at that are inside your budget. People might have specific experiences they can share.

35k won't buy (m)any new 7 seaters soo you are most likely looking at used which brings in many other variables to the equation.