Last year I asked a few questions related to proofreading. I was a newbie and did not know about this question ban related thing. I have been wanting to ask one question from last one month but cannot ask due to question ban. Today I read about question ban and found thatafter 6 months an account holder can get opportunity to ask new question. Now my concern is that my question ban is more than 6 months old and I have not yet received my question. Please help.
I can't tell when your question ban was imposed. It's an automated ban imposed by the system and moderators cannot do anything to change it.
I have found that you posted a question on March 25, after seeing a warning about the quality of past questions. You deleted that question after eight minutes, but — although I can't see when the ban was imposed — I suspect that that used the opportunity to post which is made available after six months.
(I put it like that because you stopped asking after eight poorly-received questions in May 2019. If that was when the ban started, then you would have been able to post in November 2019. You used that privilege in March 2020.)
Deleted questions count towards the quality calculation. This means that deleting downvoted questions cannot stave off the ban: those questions have still been asked. Your most recent question was neutral, not downvoted or upvoted; however, it was still posted.
Since you were able to post on March 25, the next opportunity will probably be on September 25.
More detail is available in another Meta question.