hi
if i purched 5$ per month plan where 1tb is availabe for transfer then if 1tb is expire what should digital ocean charge after 1tb will complate and if 1tb is consume then speed is slow of site?
Sorry I just have to say this but I wasn't able to understand a single word of that question
No matter, I believe what you're asking is when you'll be billed and what happens if your website exceeds 1TB bandwidth. All of this is answered in the FAQ about billing so I suggest looking there.
Per the Policy FAQ:
Do you charge for bandwidth?
Yes. Plans start with 1TB per month and increase incrementally. Once the monthly transfer limit has been exceeded, the cost of bandwidth is $0.02 per GB over the limit.