Hello SaiKishore1007
The line from Lucerne to Interlaken Ost is named Luzern Interlaken Express. It is part of the Golden Pass route, but the trains are operated by Zentralbahn and not MOB. The entire Golden Pass line consists of three different railway operators: Zentralbahn, BLS, and MOB.
Due to construction works, there are no direct trains from Lucerne to Interlaken Ost. We informed here, but since you posted in the German-speaking SBB Community, the information did not appear in English: PE Lucerne-Interlaken Express: line interruption from 2 October to 26 November 2023 - construction
There are no trains between Giswil and Meiringen, actually the most scenic part of the line. Trains will be replaced by buses, you can find the timetable on sbb-tickets.cc/en. To get the timetable, you have to enter From: Luzern To: Interlaken Ost Via: Meiringen. Due to construction works, the timetable defaults you to travelling via Bern.
Kind regards,
Roland