There is no one Answer / Reason as to aversion in providing information by the concerned "Public Information Officers" (PIO) under RTI Act.
The PIO might not provide the information sought by you due to multiple reasons such as addressed to inappropriate authority, multiple transfer of the application / bulk questions / vague query / old records / situation based queries, etc. thus hindering the promotion of transparency of the Act. In such case where the PIO failed to respond within the stipulated time frame, you can apply a First Appeal under Section 19 (1) of the Act. This will involve the higher authority who in return should direct the PIO to respond to the RTI or take necessary actions.
You can also raise a Complaint against any PIO or Appellate Authority to the concerned State Information Commission or Central Information Commission as the case maybe under Section 18 (1) of the Act if you are of the opinion that there has been an aversion / delay by the Authorities.
To know about procedure to file RTI Applications, please refer https://onlinerti.com/