Yes, in certain situations RTI can deny to provide.The right to information is not absolute. Section 8 of the Act mentions exemptions under which PIO is not obliged to provide the information. The exemptions under section 8 are as follows:
(a) information, disclosure of which would prejudicially affect the sovereignty and integrity of India, the security, strategic, scientific or economic interests of the State, relation with foreign State or lead to incitement of an offence;
(b) information which has been expressly forbidden to be published by any court of law or tribunal or the disclosure of which may constitute contempt of court;
(c) information, the disclosure of which would cause a breach of privilege of Parliament or the State Legislature;
(d) information including commercial confidence, trade secrets or intellectual property, the disclosure of which would harm the competitive position of a third party, unless the competent authority is satisfied that larger public interest warrants the disclosure of such information;
(e) information available to a person in his fiduciary relationship, unless the competent authority is satisfied that the larger public interest warrants the disclosure of such information;
(f) information received in confidence from foreign government;
(g) information, the disclosure of which would endanger the life or physical safety of any person or identify the source of information or assistance given in confidence for law enforcement or security purposes;
(h) information which would impede the process of investigation or apprehension or prosecution of offenders;
(i) cabinet papers including records of deliberations of the Council of Ministers, Secretaries and other officers: Provided that the decisions of Council of Ministers, the reasons thereof, and the material on the basis of which the decisions were taken shall be made public after the decision has been taken, and the matter is complete, or over: Provided further that those matters which come under the exemptions specified in this section shall not be disclosed;
(j) information which relates to personal information the disclosure of which has not relationship to any public activity or interest, or which would cause unwarranted invasion of the privacy of the individual unless the Central Public Information Officer or the State Public Information Officer or the appellate authority, as the case may be, is satisfied that the larger public interest justifies the disclosure of such information: Provided that the information, which cannot be denied to the Parliament or a State Legislature shall not be denied to any person.
Under section 22 also there are list of organizations on which RTI is not applicable some examples are CISF, BSF, DRDO, Assam refiles etc.