So recently when i was doing F/Uf method manually i got the notification saying certain thing limit to protect community
Can anybody tell me what should i do now?
You should go slower, and implement a warmup before doing F/U at a fast pace 
There isn’t only 1 way to warmup your account. Just think about going slow for a few weeks, by going slowly faster, and then you’ll be pretty safe!
Basically you got blocked for going to fast or doing too many actions. Do things like a normal person would do them. Not follow 200 people out of the blue.
@denis1 has some great points to add
You should stop doing F/U for at least 24 hours. You can try again tomorrow. Start with low number of actions and do other actions such as leaving a few comments and likes, viewing stories, browsing explore page and other profiles to make the account look more natural.