Improve the bracketed part of the sentence.
Jeevan knew (he were in trouble as soon as) he saw Rukmini coming towards him.
The sentence uses the third person singular noun 'Jeevan', so the corresponding verb must also reflect this. So, the verb must be the past tense 'was' and not 'were'. The conjunction phrase 'as soon as' is used to show two events happening immediately one after another. So, here, both the prepositions would be 'as'.
Therefore, the correct answer is option 3.
Improved sentence - Jeevan knew $he was in trouble as soon as he saw Rukmini coming towards him.$