Yes, it is not yet confirmed by cvs that he is akaash but there are many hints which point that Aryan is Akaash
1) He hates princesses and royal people
2) He doesnot want JN to tell anyone that he resembles Akaash so he kidnapped her! Why does it bother him if JN says to people or family that he looks like a dead person. JN was not going to media but just telling her sister. yeah.. her sister is manyata so he doesnot want Manyata to know that he is alive??
-3) When Manyata phoned JN (when she was kidnapped), he answered JN's call and didnot keep the phone down when Manyata said hello. He kept on holding the phone and as soon as Uday come on phone, he got extremely pissed off and threw the phone down. Why would he answer phone of the person he kidnapped, stay silent when a girl answers but when a guy comes on phone, he throws the phone away. He was angry and bothered that uday was with manyata and that's why he threw the phone away in disgust
4) As soon as Jagat told him that JN's sister is getting engaged, he was upset. Jagat mentioned manyata's name later in the conversation. He was soo upset and angry that he was driving his car like a madman and not even listening or caring for his girlfriend's welfare.
There were other hints in his conversation with jagat as well where he mentioned that Jagat stood by him when no one else did.
Hope this clears your confusion.