What is the timeline for getting a green card through marriage for an individual currently living in the US under H-1B status?

About 6-8 months. You will receive a travel permit and work authorization 90 days from filing

Assuming you file the I-130/I-485 package concurrently, you will receive your employment authorization document approximately 90 days after filing. In NYC, you should get your green card in about 8-10 months.

First your spouse would have to file an immigrant visa petition for you. You would have to file for adjustment of status. The processing time ranges from 3 - 12 months. It take at least 90 days to get employment authorization.

Same as anyone else. If done correctly the first time, then; 1. 70-90 days from receipt. 2. 3-6 months, depending on how busy your local CIS district office is.

about 5-6 months from filing of the completed applications correctly.

The process takes between 6 to 12 months, but the employment authorization is generally processed between 60-90 dys. If you do not retain an attorney, the process is likely to take longer as you are not familiar with the process and could leave out important forms and information.