Do I needs surgery ? Is it must ?

Surgery , usually is the last option of the treatment
Generally, patient is asked to take complete rest, with some medicines and some exercises. If he is not improved, he can be given a trial of epidural injection. And failing to it, he might require surgery
Only in few cases, where patient is having severe pain inspite of all treatment, he is not able to sit , he has developed problem in bladder or bowel habits, or has developed weakness of the foot or entire leg, he will require urgent surgery

  If I go for surgery will I have paraplegia paralysis?

With availability of newer technique and the expertise of the surgeons,now-a-days, if pt is not having any paralysis prior to surgery , he is less likely to develop it during or after surgery.(deformity correction should be considerd separately for this issue)
If patient of traumatic injury or any other problem, into which, he already having neurological deficit at the time of consultation or hospitalization, then it might happen that it would not recover after operation. But generally your doctor guides you about that , if it is the case with you

  eWhat kind of surgery you will perform?

It depends upon your problem I.e.

1  Slip disc --- microscopic discectomy or endoscopic discectomy or foraminotomy, or discectomy with fusion if there is associated instability.
2  spinal canal stenosis ,-- laminectomy and decompression or decompression with fusion—TLIF , PLIF, XLIF,
3  listhesis (slidding vertebra) – reduction of slip + decompression + fusion ,
4  osteoporotic wedging of vertebra - vertebroplasty or kyphoplasty
5  koch’s spine – decompression with stabilization of vertebra with fusion
6  traumatic spine injury -- fixation with decompression and correction of collapse if any

  What will be full duration for surgery ?

Surgery duration depend on the type of surgery. i.e.
Micro-discectomy takes around 35-40 mins.
Deformity correction --- few hours ( ranging from 3-4 hrs to 12-15 hrs also)

  Is surgery will in local anaesthesia/general?

It depend upon the type of surgery again
Most of surgeries require general anaesthesia, but endoscopic discectomy is done under local anaesthesia.
If pt can not tolerate general anaesthesia, it can be performed under local anaesthesia

  How many day I have to stay in hospital?

Depends upon the type of surgery performed I.e.
For Prolapse intervertebral disc (PIVD) operated patient 3 days,
Laminectomy 4 days,
pedicular screw fixation 5 days,
tuberculosis of spine, scoliosis, correction 7 days.