Qestion

I think so cause one time a manga I was reading was dropped for like 4 years but then there was updates again

it can happen but most of the time it wont get pick up again ╥﹏╥

Highly unlikely, but it's been known to happen from time to time. D-Gray Man was on hiatus for many years and the author has just recently resumed work on it. The only thing you can do is hope for the best and keep your fingers crossed! :)

Do you know if there is any way to raise the odds of it (the Manga, etc.) getting picked backed up, and thanks for responding to my qestion.

Aaah, it's all in the hands of the mangaka. If they decided to drop a series coz of lack of inspiration or health issues or whatever else reason, you can't pressure a mangaka. No matter how much fans flail and plead online, ultimately, a manga series is an artist's baby, their product, if for whatever reason, they decide they're done with it, that's it, game over. Not much else fans can do than accept it for what it is.

Publishers too, manga has to sell sufficiently as well. Some of them get dropped by publishers

Most of them is because the publisher dropped it, some cases involve the mangaka's heath or interest, but it's usually the publisher who decides. Sometimes a mangaka crosses a line, a guideline or "law" more specifically that cannot be erased anymore, this usually happens when the industry is more lax and toleratable towards stories, but sometimes the government ir parents start interfering.

A great example, however not confirmed of course (they usually don't publish the truth if it's taboo) is a popular manga were one of the "main" charcters died because of drugs overdose. the manga itself is a shoujo manga and published in a shoujozine, the publisher got a lot of furious comments on it from parents and probably had some negativet treats from higher up as well, hence the manga went on hiatus, but instead they said the mangaka had broken her wrist as excuse(this might be true, not sure though) It was a best selling manga at that time and even now many people are hoping for it to continue, because there are too many left in the open without a closure. The mangaka has heaed by now as it has been years she also tweeted about it when she was recovered. But even now the manga remains on hiatus despite it being a best seller. Nor has the mangaka made a comeback with another story.

It is said when mangaka and editors crosses lines they can het sagged, but I'm not sure if this is true because I don't work in the industry myself. Sorry for the long post :') I'm not posting the name of the manga because I don't want to spoil people even if it's on hiatus, it's one of the best mangas I've read in my life

- If it's dropped by mangaka, the chance is almost 0.
- In case it's dropped by scanlating group because of LC or whatever, if it's popular manga, we eventually somehow can read it later though some took years.

What is the most effective way of telling how the (the Manga, etc.) has been dropped by the Author, Publisher or Scanlating group

If dropped by the Scanlating group is there anything that can be done about it?

They announce then info's everywhere. For example of mangaka dropped, look at status
https://www.mangaupdates.com/series.html?id=33752
https://www.mangaupdates.com/series.html?id=50164
I also comment on the hiatus manga which one's dropped by whom.

Okay, this really helped me out a lot. Thanks.

Bonus Question:
Can you answer this:

Do you know if creators dropped the series as artist couldn't carry out two projects simultaneously due to his poor health is there a chance or what are the odds of him, once he finishes his current series, that him will resume working on the dropped series?

They have to make up the nice announcement to calm readers/fans. Who knows the real reason? Keep in mind that manga's also business with many people & factors involve. So.. for your question, even the mangaka may also can't reply.