Is Jnana means knowledge alone or knowledge by experience in Hinduism?
According to Ramanujacharya in the Sri Bhashya, the word jnana in the Upanishads means something more than an intellectual understanding of the texts, but instead means direct, self-realization of Brahman.
He says,
But a distinction has here to be made regarding the nature of this
knowledge which the Vedânta-texts aim at enjoining for the purpose of
putting an end to Nescience. Is it merely the knowledge of the sense
of sentences which originates from the sentences? or is it knowledge
in the form of meditation (upâsana) which has the knowledge just
referred to as its antecedent? It cannot be knowledge of the former
kind: for such knowledge springs from the mere apprehension of the
sentence, apart from any special injunction, and moreover we do not
observe that the cessation of Nescience is effected by such knowledge
merely.
...
Hence we conclude that the knowledge which the Vedânta-texts aim at inculcating is a knowledge other than the mere knowledge of the sense of sentences, and denoted by 'dhyâna,' 'upâsanâ' (i. e. meditation), and similar terms.
And what exactly is this nature of meditation?
'Meditation' means steady remembrance, i.e. a continuity of steady remembrance, uninterrupted like the flow of oil
...
Such remembrance is of the same character (form) as seeing (intuition);
...
And this being so, we conclude that the passage 'the Self is to be seen' teaches that 'Meditation' has the character of 'seeing' or 'intuition.' And that remembrance has the character of 'seeing' is due to the element of imagination (representation) which prevails in it. All this has been set forth at length by the Vâkyakâra.
...
The Vâkyakâra then goes on 'Meditation is steady remembrance, on the ground of observation and statement.' That means--this knowledge, of the form of meditation, and repeated more than once, is of the nature of steady remembrance.
Such remembrance has been declared to be of the character of 'seeing,' and this character of seeing consists in its possessing the character of immediate presentation (pratyakshatâ).
So as you can see, the word jnana in the Upanishads means intuition, which is something more than an academic understanding of a subject.