Is there any restriction on the number of UPSC attempts based on educational background?

No, there is no restriction on the number of attempts based on your educational background. The UPSC follows a "level playing field" policy where your choice of graduation stream, your percentage of marks, or the prestige of your university has no impact on your eligibility or the number of times you can sit for the exam.
The only academic requirement is that you must hold a degree from a recognized university in any discipline. Whether you are a doctor, engineer, artist, or a graduate from a distance-learning program, the rules remain the same.

The number of attempts is strictly determined by your social category and age limit:

• General/EWS: 6 attempts up to age 32.
• OBC: 9 attempts up to age 35.
• SC/ST: Unlimited attempts until age 37.
• PwBD: 9 attempts for General/OBC and unlimited for SC/ST, up to age 42.
  As long as you possess a basic degree and fall within these category-specific age and attempt brackets, your educational history will not limit your opportunities.