Build for 900eur for graphic design

I would say wait for ryzen to fully come out, but based on the following link, the i7 6700k's single core performance is what matters most: https://www.pugetsystems.com/labs/articles/AutoDesk-3ds-Max-2017-CPU-Performance-823/

What you have there is a good start, but I'd say get the k version of either the i7 6700 or the 7700. The 7700k seems to overclock better, so on average, it has even better single core performance than the 6700k.

Another question is does he care about the size of the system? This effects which motherboard, case, and CPU cooler you get.
ATX vs. Micro ATX vs. mini ITX

To overclock the CPU, you need a good motherboard and CPU Cooler.

For the motherboard, I'd say get a z270 for the i7 7700k or a z170 for the i7 6700k. (A z270 will also work for the i7 6700k, but will probably be more expensive. A z170 may work for the i7 7700k, but will probably need a BIOS update)

For the CPU cooler I'd say get the Noctua NH-D15, Corsair H110i GTX, or Kraken x61 or x62. I have the NHD15 and overclocked my i7 6800k to 4.2 GHz on it. It stays silent and cool, but the the cooler is so huge that it's hard to work on the system once you install it. If you decide to get a smaller system (mini ITX, for example), you may need to get a smaller cooler like the Corsair H100i gtx.

Good choice on the RAM. Just get the best deal on 2 x 8 DDR4 when the time comes to buy it.

For the SSD, I'd say spend a little extra for the 500GB because 250 goes fast.

For GPU, note that 3ds max only officially supports Quadro, but GeForce normally works well. The GTX 1060 3gb would be much better than the gtx 1050ti.

For PSU, get a T1 or T2 from here: http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html
A couple I found were the Antec earthwatts green 380W 80 + Bronze and the Seasonic that I have in the list.

Considering all of the above, I put this together:
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-7700K 4.2GHz Quad-Core Processor ($338.89 @ OutletPC)
CPU Cooler: NZXT Kraken X61 106.1 CFM Liquid CPU Cooler ($119.99 @ B&H)
Motherboard: MSI Z270 SLI PLUS ATX LGA1151 Motherboard ($133.98 @ Newegg)
Memory: G.Skill Aegis 16GB (2 x 8GB) DDR4-2400 Memory ($88.99 @ Newegg)
Storage: Samsung 850 EVO-Series 500GB 2.5" Solid State Drive ($159.99 @ Jet)
Video Card: EVGA GeForce GTX 1060 3GB 3GB GAMING Video Card ($189.99 @ B&H)
Case: Fractal Design Core 2300 ATX Mid Tower Case ($49.99 @ NCIX US)
Power Supply: SeaSonic S12II 430W 80+ Bronze Certified ATX Power Supply ($46.98 @ Newegg)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer ($17.88 @ OutletPC)
Operating System: Microsoft Windows 10 Home OEM 64-bit ($89.99 @ NCIX US)
Total: $1236.67
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-02-28 11:10 EST-0500

It is slightly overbudget, but if you really can't afford it, then don't buy the GPU yet. You can get by on the integrated graphics for a little while until you have enough money to buy that graphics card.

Also, getting the 250 GB SSD and the 1TB HDD may be better for the money than just the 1 500GB SSD if he's okay with moving files over to the HDD pretty frequently.

It would also save about $50 to get the i7 6700k and a good z170 board instead of i7 7700k and z270.