Explanation:

Under Ryotwari system, revenue was directly settled with the peasants and revenue rates were revised after every 30 years on the basis of land survey. - This statement is  Correct . The Ryotwari system was introduced by the British in parts of India, notably in Madras, Bombay, and some other areas. Under this system, the settlement of land revenue was made directly with the individual cultivator (ryot). 

The Mahalwari system was introduced in Madras, Bombay, Coorg, and Central Provinces. - This statement is incorrect. The Mahalwari system was introduced in parts of North and Central India, especially in the North-Western Provinces, parts of Central Provinces, and parts of Punjab. It was not introduced in Madras, Bombay, or Coorg.

Given the above analysis, the correct answer is:

1 only