Don't be judgmental with the above title. I explain the difference between pay to put somebody in jail and pay to stay in the jail concept, but these words have a more specific meaning when it comes to the law.

What rule says:
The concept of pay to put somebody in jail in a civil case is well defined in the code of civil procedure 1908.

For Example, Mr.A owes Rs 25000 money to Mr.B despite said time limit to repay the money by Mr.B, Then B file a case against Mr.A for recovery of money and send to jail, If Mr.A fail to the execution of court decree.

Under order XXI Rule 39 (3) The Monthly allowance fixed by the court shall be supplied by the party on whose application the judgment debtor (Mr.A) has been arrested by monthly payments in advance before the first day of each month(5) Sums disbursed by the decree-holder for the subsistence of the judgment debtor in the civil prison shall be deemed to be costs in the suit:
Provided that the judgment debtor shall not be detained in the civil prison or arrested on account of any sum so disbursed.

In a simplified version of the above rule:
Those who file the suit need to pay the cost to put the defendant in jail – Cost should be bear by him else.

He/she can’t be imprisoned.

Difficult to believe that what rule says, hence most of them never prefer for civil imprisonment judgment debtor so they try to attach immovable property.

Section 51 of the Code of Civil Prison. If the court for reason in writing has satisfied
(a) that the judgment-debtor, with the object or effect of obstructing or delaying the execution of the decree-
(i) is likely to abscond or leave the local limits of the jurisdiction of the Court, or

(ii) has, after the institution of the suit in which the decree was passed, dishonestly transferred, concealed, or removed any part of his property, or committed any other act of bad faith in relation to his property, or

(b) that the judgment-debtor has or has had the date of the decree, the means to pay the amount of the decree or some substantial part thereof and refuses or neglects or has refused or neglected to pay the same, or

(c) that the decree is for a sum for which the judgment-debtor was bound in a fiduciary capacity to account.

Explanation.-In the calculation of the means of the judgment-debtor for the purposes of clause (b), there shall be left out of account any property which, by or under any law or custom having the force of law for the time being in force, is exempt from attachment in execution of the decree.

Section 58
Section 58 reads as under:
Detention and release-(1) Every person detained in the civil prison in execution of a decree shall be so detained-
Where the decree is for the payment of a sum of money exceeding five thousand rupees, for a period not exceeding three months, and where the decree is for the payment of a sum of money exceeding two thousand rupees, but not exceeding five thousand rupees, for a period not exceeding six weeks:
Provided that he shall be released from such detention before the expiration of the said period of detention-
on the decree against him being otherwise fully satisfied, oron the amount mentioned in the warrant for his detention being paid to the officer-in-charge of the civil prison, oron the request of the person on whose application he has been so detained, or on the omission by the person, on whose application he has been so detained, to pay subsistence allowance:
Provided also, that he shall not be released from such detention under Clause (ii) or Clause (iii), without the order of the Court.

(1-A) For the removal of doubts, it is hereby declared that no order for detention of the judgment-debtor in civil prison in execution of a decree for the payment of money shall be made, where the total amount of the decree does not exceed two thousand rupees.

(2) A judgment-debtor released from detention under this section shall not merely by reason of his release be discharged from his debt, but he shall not be liable to be re-arrested under the decree in execution of which he was detained in the civil prison.

Pay to stay in jail Its new concept introduced by the Telangana Prison Department runs the unique jail tourism programme called "Feel The Jail" where a common man can spend 24 hours inside the Sanga Reddy Prison. where anyone can stay and experience the life of a prisoner by paying Rs 500 for a day

Conclusion.
The above rule of the code of civil of procedure needs to change because word imprisonment always creates fear in the mind of wrongdoer, in such case if affected party need to pay to the court not all of them are afforded. Thisrule needs to be amended as to include the cost of imprisonment to be bear by the judgment debtor only will then justice will be served.

References.
Code of Civil procedure 1908
https://www.indiatoday.in/india/story/jail-tourism-2-malaysians-spend-2-days-in-telangana-s-sangareddy-prison-to-experience-prisoners-life-1156088-2018-01-28