Please clear it. Of practo doctors.

Nerve is exposed and tooth is discolored so rct is compulsory

Your teeth is highly discolored.  Most of the time the pulp of the tooth undergoes certain changes if it is injured or decayed  but may remain asymptomatic.  If we place a cap in these situations , on a later day if the tooth gets symptomatic then the root canal treatment can only  be done after removing the cap. This puts more cost burden on the patient . Out of experience we know that these teeth require a  simple straightforward root canal treatment if done well will last for decades without any trouble. So the sequence should be RCT followed by filling and cap.  In your case we can attempt a crown or cap without RCT . But a pulp vitality test should be done prior to preparing the tooth for  the crown.  Based on that we can decide if we really need to do a RCT.  But if the teeth hurts after fixing the cap  ( may be immediately  or after few years ) you have to sacrifice the cap and redo a new one .

xray required to confirm if RCT is needed. photos not enough for diagnosing.

It's too deep to involve the layer which consists of nerve and blood vessels. Once that later is reached, Rct is only way of treating the tooth for removing the whole infected region for complete cure. Followed by crown for enhancing strength of the tooth.