Answer:
Rohan asked me when ,I was arriving.
Step-by-step explanation:
While changing speech from direct to indirect change of tense is always carried in reported speech when past tense is used in the reporting speech. In such a case the tense in the reported speech shifts to the next tense. As the tense in the reported speech is past indefinite and is followed by past continuous tense. So, the tense of reported speech is shifted to past continuous tense using second form of "was" as helping verb along with the present participle i.e arriving.