Broken stud connecting the exhaust. Try drilling it without success. Don’t have welding gear. Is it ok if i only use i bolt and leave the broken one as it is?

 

The exhaust will not seal with just one bolt. What type of easy out system did you use? Doesn't look like the bolt was drilled at all.

 

i would not run it like that it will leak and the engine will not perform properly and possibly cause damage... Judging by how the hole looks someone has overtightened it at some point and it was loose at some point as well. Definitely does not looked drilled, you are going to have to remove the pipe so you can work better, center punch it, start out with smaller drill bits and work your way up until you get to the one you need for a easy out. Go slow and easy with the drill bits as it is very easy to snap them off.. Use a little heat from a propane torch before getting the easy out on it... If you have never done this before i would recommend you take it to a shop or a welding shop and pay the money to get it done... You can really screw this up easily if you get impatient and it could be money well spend to pay a hour of shop time to get it out especially if you get everything off for the shop so all they have to do is tackle the broken stud

 

I mostly agree with Zrock. if you have no experience take it to a shop and have them remove it. but if you have some experience and patience get out your center punch lubricating fluid and torch and pull that out.