if the bowler for some reason happens to bowl no-ball again and again, what are the possible scenarios?
Then the batting team gets lots of free runs. Don't use bowlers who can't bowl a legal delivery.
Can the bowling team or the captain change the bowler?
In general, no. Law 17.7.1:
Other than at the end of an innings, a bowler shall finish an over in progress unless incapacitated or suspended under any of the Laws.
This also answers your next question - if a bowler is genuinely injured, they can be replaced.
Or say he is fixing.
If by this you mean the bowler is engaged in match-fixing, the team has far, far bigger problems. The captain should probably explain the issue to the umpires, who will probably then immediately suspend the match and allow the governing body and/or legal processes to sort it out.