You need "the" before "signature" in the first. Otherwise they are OK.
Student or Learner
Will signature of Ram be needed for payment ?
He will be punished.
Are the above sentences correct? Which tense are the above sentences? [I understand the above sentences are in passive voice.]
"... the signature of Ram" is rather unnatural. Just use the possessive. "Will Ram's signature be needed for payment?"
"He will be punished" is OK.
What tense do you think they use?
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
It's a passive, so we have will + be + past participle. If you use the present it would be is punished, and was punished for the past. The tense is shown in the verb be. The active form would be someone will punish him.