What is the approximate EB-5 processing time for investors from India?

Your summary seems to be referring to the Chinese investors. The processing times for Indian investors are lesser than for the Chinese. The I-526 petitions of Indian nationals take about 20 months. As to when either I-485 or DS-260 can be filed, look to the monthly Visa Bulletin published by the State Department. Lastly, the Visa Bulletin usually shows that the processing times for Indian investors change from time to time.

The 3 to 4 years of waiting is reasonably accurate for current processing times. The date for the priority date to be current is only a guess. You can review years of Visa Bulletins to try and figure out a pattern. These come out every month.

It is taking about two years to adjudicate and in November last year, the State Department provided an unofficial estimate of about 6.7 years for newly filed cases.

There is a wait for a green card after I-526 approval. I-526 approvals come in about two to four years. The filing of the I-526 establishes the priority date for a green card. When the I-526 is approved, we check the Department of State Visa Bulletin to see what priority dates are being processed, and move forward from there. If the delay in green cards for Indians gets longer and longer, it may indeed be many years, like the Indian EB-2 and EB-3 processes.