According to a survey conducted in Tamilnadu, the RTO office is the most corrupt closely followed by Registration dept. In these departments nothing can be done without giving extra money. The police and sales tax depts are a distant third and fourth.
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According to a recent survey by an independent NGO, the most corrupted department in our country is Police department. They are charged with extremely higher rates of corruption. When a cop is determined to take bribe there is no way to bend him if you are a common man.