Does google ban if my forum contain thread like " female condom, aids, mentraul etc." ?

No, Why would they?

they do ban if you place adsense in a porn site or any other heavily illegal website, if someone in ur forum mentioned the word condom, the maximum u can get is durex ads displayed

These are the things web sites may not include from Google's Program Policies.

Site may not include:

• Excessive profanity
• Violence, racial intolerance, or advocate against any individual, group, or organization
• Hacking/cracking content
• Illicit drugs and drug paraphernalia
• Pornography, adult, or mature content
• Gambling or casino-related content
• Excessive advertising
• Any other content that promotes illegal activity or infringes on the legal rights of others
• Pop-ups, pop-unders or exit windows that interfere with site navigation, obscure Google ads, change user preferences, or are for downloads. Other types of pop-ups, pop-unders, or exit windows may be allowed, provided that they do not exceed a combined total of 5 per user session
• Excessive, repetitive, or irrelevant keywords in the content or code of web pages
• Deceptive or manipulative content or construction to improve your site's search engine ranking, e.g., your site's PageRank
• Incentives (monetary or point-based) to users or third-party beneficiaries for online activity including, but not limited to, clicking on ads or links, performing searches, surfing websites, reading emails, or completing surveys
• Sales or promotion of certain weapons, such as firearms, ammunition, balisongs, butterfly knives, and brass knuckles
• Sales or promotion of beer or hard alcohol
• Sales or promotion of tobacco or tobacco-related products
• Sales or promotion of prescription drugs
• Sales or promotion of products that are replicas or imitations of designer goods