Is it wise to stay there hoping someday I will be tagged to the proper project?
You have several options, but surely staying and just hoping to be tagged to the projects you like isn't the best you can do.
It's worth mentioning that not all the time you get the projects you would like doing the most. Sometimes you get projects that may not be the most interesting and sometimes you get some on your favorite topic.
That being said, if you see that many of the projects they do are not the "proper" projects for you, and being assigned to them seems unlikely, then considering other jobs is a wise option.
If I leave, will this affect my resume? I mean leaving the 2nd job in 9 months and 3rd in 6 months.
I think not, it won't look bad.
Its commonly advised to include on your resume jobs that you were at least 6 months, as that one could say is the "minimum" time considered for a job to be "worth" including on your resume. All your jobs have that minimum, besides 3.1 years on one place suggests stability despite your actual trend.
Is it wise to stay for 6 more months i.e a year in the current job?
Staying against your will and without being motivated is not a wise idea. You will end up burnt out, only to make your resume look a bit "better".
Like I said, 6 month jobs are not red flags. Given that you currently only have one 6 month job I would not worry. However, I would also advice you to stop that trend, as several 6 month jobs can eventually raise some flags.