In telegram we can chat but not reliable and very slow performance, it is very unuseful app . we cannot send more contacts at a time, attachments are not working properly and sometimes it is shown wrong last seen.
While comparing with other chattingapps it is very poor performance and at the time of sending attachments app becomes very slow and even not responding and not going also, though we have full internet facility sometimes messages struck, but that messages not go even after 2 days also and wecan mis offline messages sometimes. it occupies more memory compared to other apps., my suggestion not go for telegram.